Chapter 7. Manipulating Tempo and Time Stretching

Lesson Files

Logic 8_Files > Lessons > 07 New Day_start

Media

Logic 8_Files > Media > New Day > Audio Files

 

Logic 8_Files > Media > Additional Media

Time

This lesson takes approximately 45 minutes to complete.

Goals

Match a project tempo to an audio file’s tempo

 

Use and customize the Loop Browser

 

Create Apple Loops

 

Make an audio region follow the project tempo

 

Insert tempo changes and tempo curves

 

Time stretch an audio region to match the project tempo

Modern music genres have seen the use of loops and samples increase exponentially over the last few years. New technologies encourage experimentation, and it is more and more common to find, say, a sample of a Middle Eastern instrument in a modern rock song, a sample of classical music in a pop song, or a sample of a pop song in a hip-hop track.

Mixing pre-recorded material into a project can lead to exciting results, but the material must be carefully selected to ensure that it seamlessly blends into the project. The first challenge is to match the tempo of the pre-recorded musical material and the tempo of a project.

In this lesson, you will import an audio file into a new project, changing the project tempo to match the audio file’s tempo. You will work with the Loop Browser to add Apple Loops to the project, customize the Loop Browser to suit your needs, and create your own Apple Loops. Finally, you will manipulate an existing project’s tempo and use different techniques to make audio files match the project’s tempo.

Matching the Project Tempo to an Audio Region’s Tempo

Sometimes you start a new project with pre-recorded material and want to use the tempo of that material for the new project. For example, you find a drum loop that you like because of the way it grooves at its original tempo. You need to adjust the project tempo to match that loop. When the project tempo matches the loop, you can use the grid to edit regions, program and quantize MIDI regions, or add Apple Loops while keeping everything synchronized with the pre-recorded drum loop.

In Lesson 3, you selected a two-bar drum pattern from a drum recording and edited it to loop perfectly in the Arrange area. In the next exercise, you will import that two-bar audio file into a new project and adjust the project tempo so that it matches the tempo of the audio file.

  1. Choose File > New (or press Command-N).

  2. In the Templates dialog, click the Empty Project template.

  3. Create a stereo audio track, and select Open Library.

  4. In the Media area, click the Browser tab.

  5. At the top of the Browser, click the Home button.

    Matching the Project Tempo to an Audio Region’s Tempo

    All the folders contained in your home folder are displayed in the Browser.

  6. Click the Browser View button.

    Matching the Project Tempo to an Audio Region’s Tempo
  7. In the left column, click the Desktop folder.

    Matching the Project Tempo to an Audio Region’s Tempo

    The contents of your desktop appear in the right column.

  8. Navigate to Logic 8_Files > Media > Additional Media.

    Locate the file named My Rock Drums Loop.aif.

    When you double-click an audio file in the Browser, an audio region is created on the selected track at the playhead position. Make sure that the playhead is placed at the beginning of the project.

  9. Double-click My Rock Drums Loop.aif.

    Matching the Project Tempo to an Audio Region’s Tempo

    The audio file is imported into the project and an audio region representing the entire audio file is inserted on the selected track, at the beginning of the project.

  10. In the Arrange area, click the My Rock Drums Loop region to give the area key focus, and press L to loop the region.

    On the Arrange area’s grid, you can see that the loop repeats don’t fall on downbeats. You can use the metronome to compare the project tempo to the audio file’s tempo.

  11. In the Transport bar, click the Metronome button.

  12. In the Arrange area, start playback.

    You can immediately tell that the drum loop is out of sync with the project.

    Before you can adjust the project tempo, you need to create a cycle area of the length that you want your audio file to match when the tempo is adjusted. My Rock Drums Loop is a two-bar audio file, so you need to create a two-bar cycle area.

  13. In the Bar ruler, click the cycle area.

    Cycle mode turns on.

  14. Adjust the cycle area so it is two bars long.

    Matching the Project Tempo to an Audio Region’s Tempo

    Now you will instruct Logic to automatically calculate the new project tempo so that the cycle area’s length matches the selected region’s length.

  15. Make sure that the region is still selected and, in the main menu bar, choose Options > Tempo > Adjust Tempo using Region Length and Locators (or press Command-T).

    Matching the Project Tempo to an Audio Region’s Tempo

    An alert message appears asking whether you want to create a tempo change, or change the global tempo of the project. In this exercise, you want to change the tempo for the entire project.

  16. Click Globally.

    Matching the Project Tempo to an Audio Region’s Tempo

    The project tempo is adjusted to 90.6733 bpm, and the My Rock Drums Loop region is exactly two bars at the new tempo.

  17. Listen to the project.

    The project tempo now matches the tempo of the audio file that you just imported, and the metronome now plays in time with the drums.

  18. Turn off the metronome.

You have matched the project’s tempo to the audio file’s tempo, and now you can start building the project using the grid. You can also add Apple Loops, and they will now automatically play in sync with your drums.

Working with Apple Loops

Apple Loops are AIFF or CAF format audio files containing additional information that allows them to automatically match the tempo and key of a Logic project. They also contain descriptive information—including instrument, genre, mood, and scale—that helps you search large libraries of Apple Loops using the Loop Browser.

More Info

Apple Loops are also supported by the GarageBand and Soundtrack Pro applications. When Apple Loops are imported into an application that does not support them, they behave like regular AIFF audio files.

Using the Loop Browser

You were introduced to the Loop Browser in Lesson 1, when you previewed and chose loops to create a project. Now, you’ll take a closer look at the Loop Browser.

  1. In the Media area, click the Loops tab.

    The Loop Browser opens. You are going to search for a major-scale acoustic guitar loop in the pop genre.

    At the top of the Loop Browser, three menus—View, Signature, and Scale—allow you to filter searches of Apple Loops by collection (Jam Pack, GarageBand, or other), time signature, and type of scale (minor or major).

  2. In the Scale menu, choose Major.

    Using the Loop Browser

    This will filter your next search to display only loops that work with a major scale. The Loop Browser needs a little more information and doesn’t display any results yet.

    At the upper right of the Loop Browser, you can choose one of three views: Column, Music, or Sound Effects. Each view enables a different way to filter the loops as they are organized in the Search Results list.

    Using the Loop Browser
  3. Click the Column View button.

    While the Music and Sound Effects views display only a selection of category buttons, the Column view lets you access all the existing descriptors: By Genres, By Instruments, and By Moods.

  4. Choose By Instruments > Acoustic Guitar > Acousti...ar (229) (the last category, Acoustic Guitar (229) is abbreviated).

    Using the Loop Browser

    The number in parentheses (229) represents the number of results that match your search and may be different depending on the number of loops installed on your computer. The 229 major-scale acoustic guitar loops are displayed in the Search Results list at the bottom of the Loop Browser.

    At the top of the Loop Browser, you can enter text in the search field and further filter the search results to display only the loops containing the search text in their names.

  5. In the search field, type pop and press Enter.

    The Search Results list now shows the 17 major-scale acoustic guitar loops that have pop in their names.

  6. Click Alt Pop Acoustic 01.

    Using the Loop Browser

    The loop starts playing. It sounds like a detuned acoustic guitar, and you may hear some weird artifacts. In fact, in the Key column, you can see the loop’s original key. This loop was performed in E major. When previewing a loop, it is transposed to match the key of the project (the default key signature for a project is C major—you will change the project’s key signature in the next exercise). The further the playback key and tempo are from the loop’s original key and tempo, the more artifacts are introduced.

    At the bottom of the Loop Browser, the preview settings let you adjust the volume and key at which you preview the loops.

  7. In the “Play in” pop-up menu, choose C#.

    Using the Loop Browser

    The loop plays in C#, one semitone higher than the project’s default key.

  8. In the “Play in” pop-up menu, choose Original Key.

    The loop plays in its original key, E major. It now sounds like an acoustic guitar playing in a regular tuning, and the artifacts disappear.

  9. Drag Alt Pop Acoustic 01 to bar 1, below the existing track in the Arrange area.

    Using the Loop Browser

    A new audio track is created, and the Alt Pop Acoustic 01 loop is inserted at bar 1.

  10. Turn off Cycle mode and listen to the project.

    The loop plays in the project’s key, C major. In the next exercise, you will change the project’s key to make that loop sound better.

Setting the Project’s Key Signature

In the previous exercise, you noticed that a loop sounds more natural when it is played in its original key. It sounds closer to the sound of a regularly tuned instrument and, since there is no transposition to process, you hear fewer artifacts. It is usually preferable to choose Apple Loops with original keys and tempos that are closest to the project’s key signature and tempo to reduce the amount of processing necessary to match the loops to the project, thereby reducing audible artifacts.

Let’s change the key of the project to E major, the original key of the acoustic guitar.

  1. In the Arrange area, make sure the Alt Pop Acoustic 01 region is still selected and press L.

    The acoustic guitar region is looped throughout the project.

  2. Start playback.

    The loop plays in C major, the key of the project.

  3. Stop playback.

    To change the project’s key signature you need to access the global Signature track.

  4. At the top left of the Arrange area, click the Global Tracks disclosure triangle.

    Setting the Project’s Key Signature

    The global Marker, Signature, and Tempo tracks are displayed. In the global Signature track you can see the time signature (4/4) and the key signature (C).

  5. Double-click the key signature (C).

    The Key Signature window opens.

  6. In the Key pop-up menu, choose E. Keep Major selected.

    Setting the Project’s Key Signature
  7. Click OK (or press Enter).

    On the global Signature track, the new key signature is E.

  8. Listen to the project.

    The loop plays in the new key signature, E major. It now sounds much more natural, and matches the drums quite well.

You used the global Signature track to set the key of your project, making sure that all Apple Loops in the project will now play at the new project key. If you want to go further and create an arrangement using Apple Loops, you can also insert key signature changes on the Signature track to build a chord progression, and all Apple Loops will change key according to the Signature track.

Customizing the Loop Browser

In the Loop Browser, the Music and Sound Effects views show only a selection of category buttons. However, you can customize the button arrangement and the category that each button displays. When previewing loops, you can mark the loops you like as favorites to access them more quickly later.

  1. In the Loop Browser, click the Music view button.

    Customizing the Loop Browser

    The Music category buttons are displayed. In the first row, the buttons are Acoustic, Bass, and All Drums. Let’s assume you work mainly with vocal loops. First, you will move the Vocals button currently located at the bottom right to the top of the view, swapping its position with the Acoustic button.

  2. Drag the Vocals button to the Acoustic button at the top of the view.

    Customizing the Loop Browser

    Note

    If you can’t see the Vocals button, drag down the two small horizontal lines between the buttons area and the search result list to expand the buttons area.

    The two buttons exchange positions.

    Now you’ll customize the second and third buttons to display categories not currently visible in Music View.

  3. Control-click the Bass button.

    Note

    A shortcut menu appears allowing you to choose any available category, as in the Column view.

  4. Choose Instruments > Vocals > Male.

    The button now shows the Male descriptor.

  5. Control-click the All Drums button and choose Instruments > Vocals > Female.

    Note

    Your three top buttons are now Vocals, Male, and Female. You can use them to browse vocal loops.

  6. In the Scale menu, choose Any.

  7. Click the Female button.

    All female voice loops are displayed in the Search Results list.

  8. Preview the loops and find one that you like.

    When searching for the perfect loop for a project, you can spend a considerable amount of time previewing loops. Often, you may find loops that you like but then decide that they won’t work with the project at hand. Instead of just moving to the next loop and forgetting about those loops, you can mark them as favorites.

  9. Select the Fav checkbox for the loop you like.

    Note

    If there are other loops you like, mark them as favorites, too.

    Now you can access all the loops you have marked as favorites.

  10. At the upper left of the category buttons, click the Reset button.

    All search terms are reset and the Search Results list is emptied.

  11. Click the Favorites button.

    Note

    All your favorite loops are displayed.

    After you customize the top category buttons to suit your needs, you may not need to display so many category buttons, and you can resize the buttons area to see more loops in the Search Results list.

  12. Drag up the two small horizontal lines between the buttons area and the Search Results list.

    Note

    The buttons area is smaller, making the Search Results list taller; and, at the bottom right of the buttons area, a new button with the >> icon allows you to access the hidden buttons.

    In the next exercises, you will open a new project, so you need to save this project.

  13. Choose File > Save (or press Command-S) to save the project to the desktop, naming it Pop Song.

By now you should understand the power and flexibility of Apple Loops. They will automatically match the tempos and key signatures of a project. You will now create your own blue and green Apple Loops.

Creating Blue Apple Loops

When you are using audio regions to create Apple Loops, you are creating blue Apple Loops. Blue Apple Loops can be used only as audio regions on audio tracks.

In the following exercise, you will open an existing project you worked on in earlier lessons, New Day, while keeping the current project open. You will create Apple Loops using material from New Day, and then return to the current project to preview and use the new Apple Loops.

  1. Keep the current project open, and open Logic 8_Files > Lessons > 07 New Day_start.

    An alert appears, asking you whether to close the current project.

  2. Click Don’t Close.

    Creating Blue Apple Loops

    07 New Day_start opens, and the current project stays open in the background.

    Tip

    If the new project’s Arrange window does not fill the screen, you can click the window’s zoom button, the third button from the left of the title bar, to make the window full screen.

    Feel free to listen to New Day if you need to refresh your memory. You will now use the Marquee tool to cut the two first bars of the High Arpeggio guitar region, and turn that two-bar arpeggio into a blue Apple Loops file. The Marquee tool is your current Command-click tool.

  3. Drag the Marquee tool over the High Arpeggio region from bar 5 to bar 7.

    Tip

    If you want, you can solo the Acoustic track and press the Spacebar to preview the Marquee selection.

  4. Click the Marquee selection with the Pointer tool.

    Tip

    The marquee selection is divided into a new region, and the new region is selected.

    You will now turn that new two-bar audio region into a blue Apple Loops file.

  5. In the Arrange area’s local menu bar, choose Region > Add to Apple Loops Library.

    Tip

    The Add Region to Apple Loops Library dialog appears. All the information you enter in this window will be used by the Loop Browser to index the loop. It is the same information you will use to search for that loop in the Loop Browser.

    Enter or choose the following information:

    • Name: High Arpeggio

    • Type: Loop

    • Scale: Minor

    • Genre: Rock/Blues

    • Instrument Descriptors: Guitars > Acoustic Guitar

    Click the tags Single, Clean, Acoustic, Relaxed, Dark, Dry, Grooving, Melodic, and Part.

    Tip

    More Info

    Using Region > Add to Apple Loops Library, you can create blue Apple Loops only when the number of bars in a selected region is a whole integer. This function uses the project tempo to tag the transient positions and works best for audio files that match the project tempo. If the selected region length is not an integer, the Type parameter will be set to One-shot and dimmed.

    To create blue Apple Loops with material that does not match the current project tempo, and to see a more refined transient analysis of your audio file, choose Audio > Open in Apple Loops Utility and use the Apple Loops Utility, as explained in Logic Pro: Beyond the Basics by David Dvorin.

  6. Click Create (or press Enter).

    More Info

    A Progress indicator shows that the audio region is bounced as a new audio file.

    More Info

    A second Progress indicator shows that the loop is indexed in the Loop Browser. Be patient. This process can take some time, depending upon the number of loops present on your system.

    When the second Progress window closes, your Apple Loops file has been created and indexed and is available in the Loop Browser. You can now access it from any project as you can any other Apple Loops file.

  7. In the Media area, click the Loops tab.

  8. At the top of the Loop Browser, in the search field, type High Arpeggio and press Enter.

    Your new acoustic guitar loop is displayed in the search results. You can click it to preview it, and play it in different keys using the “Play in” menu at the lower right of the Loop Browser.

    You will now mark High Arpeggio as a favorite so that you can easily find it when you need it later in this lesson.

  9. Select the Fav checkbox for High Arpeggio.

    More Info

    In the Arrange area, you will now heal the High Arpeggio region.

  10. From the main menu bar, choose Edit > Undo Split Regions (or press Command-Z).

    In the Arrange area, the High Arpeggio regions are healed back to a single region.

  11. In the Arrange area, click the background to undo the marquee selection.

You have created a blue Apple Loops file from a portion of an audio region, and restored the project to its original state so that you can continue to work in it later in this lesson.

Creating Green Apple Loops

When you use MIDI regions on a software instrument track to create Apple Loops, you are creating green Apple Loops. Like the blue loops, the green Apple Loops are AIFF or CAF audio files that can be used as audio regions on an audio track; but they also contain the original MIDI region and software instrument channel strip settings that were used to create them, so you can also use them as MIDI regions on software instrument tracks.

You will use the same process as in the previous exercise to create a green Apple Loops file using the High Pitch Synth on track 8.

  1. In the Arrange area, select the High Pitch Synth region on track 8, at bar 15.

    Creating Green Apple Loops
  2. In the Arrange area’s local menu bar, choose Region > Add to Apple Loops Library.

    The Add Region to Apple Loops Library dialog appears.

    Enter or choose the following information:

    • Name: High Pitch Synth

    • Type: Loop

    • Scale: Minor

    • Genre: Electronic

    • Instrument Descriptors: Keyboards > Synths

    Click the tags Single, Distorted, Electric, Intense, Dark, Processed, Grooving, Melodic, and Part.

    Creating Green Apple Loops
  3. Click Create (or press Enter).

    Wait for the two Progress windows to disappear, indicating that your Apple Loops file has been created and indexed in the Loop Browser. You will use that loop in the next exercise.

Using the New Apple Loops in Another Project

You will now switch to the Pop Song project you were working on before you opened New Day, use the Loop Browser to find your new Apple Loops, and add one of them to the project.

  1. From the main menu bar, choose Window > Pop Song – Arrange (at the bottom of the Window menu).

    Now preview your new High Arpeggio Apple Loops file in the Loop Browser. The Loop Browser is currently displaying your favorites, but you may have to refresh it to see the loop you just marked as a favorite.

  2. Click the Favorites button to disable it, then click it again to enable it.

    The list of favorites is refreshed, and you should now see your High Arpeggio loop.

  3. At the bottom of the Loop Browser, in the “Play in” pop-up menu, choose Song Key.

  4. Start playing the project.

  5. In the Loop Browser, click the High Arpeggio loop to preview it while the song is playing.

    High Arpeggio plays in E (the project’s key). However, the loop was performed in a minor key and doesn’t work well with the major acoustic guitar loop. Let’s try the High Pitch Synth green loop.

  6. In the Loop Browser, resize the buttons area to see all the category buttons.

  7. Click the Reset button to clear your current search.

  8. Click the following category buttons:

    • Distorted

    • Electronic

    • Melodic

    • Dark

    Using the New Apple Loops in Another Project

    A few loops appear in the Search Results list, including your new green Apple Loops file, High Pitch Synth.

  9. Click your loop to preview it along with the project.

    If necessary, adjust the volume slider at the bottom of the Loops browser to hear the High Pitch Synth loop. That loop works pretty well.

  10. Stop playback.

  11. Drag High Pitch Synth to bar 1 in the Arrange area, below track 2.

    Using the New Apple Loops in Another Project

    A new software instrument track is created, the loop’s channel strip setting is loaded, and the loop’s MIDI region is inserted on the new track.

  12. Select the new software instrument track header (track 3), and in the Inspector, reduce the Arrange channel strip fader level to –17(dB).

  13. Press L to loop the High Pitch Synth region.

  14. Start playback.

    The new loop adds an interesting sound to the song, but its rhythm doesn’t work well with the drum groove. However, green Apple Loops have a big advantage over blue loops: when you insert a green loop into a software instrument track, you can still edit the MIDI region or tweak the channel strip setting. In this case, you could use that new software instrument channel strip settings, and program or record a new MIDI region that works better with the song.

  15. Save the Pop Song project and close it.

    The project closes, and you can see the New Day project again. You will work in New Day for the remainder of this lesson, so keep it open.

Remember the distinction between blue and green Apple Loops when you preview loops in the Loop Browser. When you like the sound of a green loop, you can add it to your project just to use the software instrument channel strip setting. Then, delete the MIDI region and record or program your own MIDI region. (That’s a good way to preview channel strip settings without loading them.) In contrast, if you like the melodic or the rhythmic pattern played by a green loop, you can add it to the Arrange area and keep only the MIDI region, using another software instrument channel strip setting.

Making Audio Files Follow the Project Tempo

When producing a song, choosing a tempo is usually one of the first decisions you make, before you do any audio recording. When a tempo is set, you can start building the project, record audio files, and match any imported audio to the project’s tempo.

However, in some cases you might decide late in the process that you want to experiment with the tempo. Maybe you realize that the song was produced too slow and it needs a little speed bump. Or maybe you want to add tempo nuances and have certain sections subtly speed up or slow down.

While all MIDI regions and Apple Loops will automatically follow any tempo changes or variations you place in your project, audio recordings won’t follow along unless you force them to do so. When an audio file is played in the same project in which it was recorded, you can use Logic’s Follow Tempo feature. The audio file is loaded into RAM and automatically matched to the project tempo.

  1. In the Transport bar, double-click the Tempo display, type 77, and press Enter.

    Making Audio Files Follow the Project Tempo
  2. Go to the beginning and start playback.

    During the introduction, the drums and bass Apple Loops play at the new tempo. As soon as the playhead reaches bar 5, you can hear the acoustic guitar still playing at the old tempo, out of sync with the project.

  3. Stop playback and click the Acoustic track header.

    Making Audio Files Follow the Project Tempo

    All the acoustic guitar regions are selected.

    Notice that the Inspector’s Region Parameter box now reads “4 selected.” Adjusting parameters in the Region Parameter box will adjust the same parameters for all four selected regions.

  4. In the Region Parameter box, select the Follow Tempo checkbox.

    Making Audio Files Follow the Project Tempo

    The selected audio regions’ lengths are adjusted, and the icon next to each region’s name turns into a double arrow, indicating that the regions now follow the project tempo.

    Making Audio Files Follow the Project Tempo

    You can’t apply fades or crossfades to a region that follows tempo, so the fades disappear.

  5. Start playback.

    This time the acoustic guitar regions match the tempo of the project, and everything is in sync.

Depending on the type of audio material and the difference between the audio file’s original tempo and the project’s tempo, you may hear artifacts when using the Follow Tempo function. But even if you have to record some parts again, Follow Tempo is a useful feature for experimenting with tempos. For example, the guitar player may already have recorded his parts, but the vocalist feels the song was recorded too slowly. Instead of waiting until the guitarist can get back into the recording studio, set the guitar recordings to follow tempo, increase the song tempo, record the vocals, and later record the guitar player at the new tempo.

Inserting Tempo Changes and Curves

When you want to vary the tempo throughout a project, you can use the global Tempo track to insert tempo changes and tempo curves. All MIDI regions, Apple Loops, and audio regions that are set to follow tempo will automatically follow the project tempo, even when tempo variations occur in the middle of regions.

  1. At the upper left of the Arrange area, click the Global Tracks disclosure triangle.

    The global Marker, Signature, and Tempo tracks are displayed.

  2. Click the global Tempo track disclosure triangle.

    Inserting Tempo Changes and Curves

    The Tempo track expands vertically. The Tempo track displays tempo changes as nodes. Lines connect the nodes, similar to the Hyper Draw automation of MIDI controllers that you explored in Lesson 5. Right now, because the entire project plays at one tempo, only one node is placed at the beginning of the project, and one horizontal line follows that node. You can see the tempo value displayed next to the node (77 bpm).

    In the Tempo track header, you can choose up to nine Alternative tempo maps. Let’s leave Alternative 1 set to 77 bpm, and choose Alternative 2. This will allow you to experiment with tempo changes in Alternative 2 while leaving Alternative 1 available at the original tempo if you are not happy with the new results.

  3. In the Tempo track header, click the Alternative menu and choose 2.

    Inserting Tempo Changes and Curves

    Tempo Alternative 2 is displayed, and the whole project is set to the default 120 bpm tempo. (Try playing the song at 120 bpm if you want a good laugh.)

    You’ll continue by adjusting the tempo to 71 bpm.

  4. In the Tempo track, position your mouse pointer over the tempo line.

    Inserting Tempo Changes and Curves

    The mouse pointer turns into the Hand tool, indicating that you can move the line.

  5. Drag the line down to 71 bpm.

    Even though the line has to be dragged below the bottom of the Tempo track and seems to disappear, keep dragging down and watch the help tag to set the tempo to 71.

    Inserting Tempo Changes and Curves

    When you release the mouse button, the scale in the Tempo track header readjusts and the line is visible again, with the new value (71 bpm) visible next to the node.

    Now insert a tempo change on bar 5.

  6. At bar 5, double-click slightly below the tempo line.

    Inserting Tempo Changes and Curves

    A new node is inserted at bar 5, and you can see the value of the new tempo displayed next to the node. Adjust the new tempo to 69 bpm.

  7. To the right of bar 5, drag the new line vertically to a value of 69.

    Inserting Tempo Changes and Curves

    When you know that you are not going to use tempos outside a certain range, you can adjust the vertical scale of the Tempo track to make it visually easier to edit tempos within that range. In this song, you won’t use tempos faster than 80 bpm or slower than 60 bpm.

  8. In the Tempo track header, drag the maximum value (100) down to 80.

    Inserting Tempo Changes and Curves
  9. Drag the minimum value up to 60.

    The new tempo scale ranges from 60 bpm to 80 bpm.

    You will now create an accelerando during the first electric piano and acoustic guitar section. The goal is to increase the tempo slowly from 69 bpm to 77 bpm. First, you have to insert a tempo change at the end of the section. Use the Pencil tool to do so. It lets you insert a tempo change and adjust its value in one operation.

  10. Press Esc and, from the Tool menu, choose the Pencil tool.

  11. At bar 9, drag the Pencil tool vertically so the tempo in the help tag reads 77.

    Inserting Tempo Changes and Curves

    To create a tempo curve between two nodes, you need to drag the deep blue node located above or below the second node.

  12. At bar 9, drag the deep blue node below the new 77 bpm tempo change, and then drag it toward the left and up.

    Inserting Tempo Changes and Curves

    You can precisely adjust the tempo curve by dragging the node farther to the left, farther up, or both.

  13. Go to the beginning of the song and start playback.

    The whole project follows the new tempo map. Depending on the Apple Loops you are using or the type of audio recordings that follow the tempo, your results may vary. Here again, drastic tempo variations may create artifacts, so let your ear be the judge. Note that percussive material usually reacts better to tempo variations than melodic and harmonic material.

    If you are not happy with your tempo experimentations, you can now revert to the first tempo alternative.

  14. In the Tempo track header, click the Alternative menu and choose 1.

    The first tempo alternative (a single tempo at 77 bpm throughout the project) is displayed in the Tempo track. The song actually sounded better at its original tempo, 73 bpm.

  15. Press Esc twice to revert the left-click tool back to the Pointer tool.

  16. Drag the tempo line down to 73 bpm.

  17. Press Esc twice to revert the left-click tool to the Pointer tool.

  18. Close the global tracks (or press G).

Time Stretching an Audio Region

In the first exercise, you used a drum audio file at its original tempo and matched the project’s tempo to the tempo of the drum region. That’s useful when you use pre-recorded material in a new project. But what if you wanted to add that drum loop to an existing project? Most of the time, you want to keep the original project tempo and adjust the loop tempo to match the project.

While Apple Loops automatically match the project tempo when you import them, other audio files always play at their original tempos. You have to time stretch an audio file to make it match the project tempo.

In this exercise, you will import the same drum audio file, and time stretch it to match the tempo of the project.

  1. In the Arrange area, select the last track (track 8) and create a new stereo audio track.

    The new stereo audio track is created in the Arrange area, below the selected track.

    You will import the drum audio file to that new track using the Browser, and use it for the end section of the song that starts on bar 15. Since double-clicking a file in the Browser inserts a region on the selected track at the playhead position, you need to position the playhead on bar 15.

  2. On your main keypad, press / (slash), the Go to Position command. In the Go To Position dialog, type 15, and press Enter.

    Time Stretching an Audio Region

    The playhead moves to bar 15.

  3. In the Media area, click the Browser tab.

  4. In the Browser, click the Project button.

    Time Stretching an Audio Region

    The Browser displays the contents of the New Day project folder.

  5. Double-click the Audio Files folder.

    You can see the project’s audio files and the file My Rock Drums Loop.aif you saved in Lesson 3.

    Note

    If you didn’t save My Rock Drums Loop in Lesson 3, go to Logic 8_Files > Media > Additional Media, and you will find an equivalent My Rock Drums Loop.aif file to use.

  6. Double-click My Rock DrumsLoop.aif.

    Note

    The My Rock Drums loop is inserted on the selected track, at bar 15. When working with audio files it’s a good idea to open the Audio Bin to keep track of the audio files added to the project.

  7. In the Media area, click the Bin tab.

    You can see My Rock Drums Loop.aif in the project’s Audio Bin.

  8. Listen to the project starting at the current playhead position, bar 15.

    The new drum audio region plays too fast. To get the best results when time stretching an audio region, select the best time-stretching algorithm for the type of material to process before you time stretch the region.

  9. In the Arrange area’s local menu bar, choose Audio > Time Machine Algorithm > Percussive.

    Note

    More Info

    You can also purchase high-quality time-stretching algorithms like iZotope Radius or Serato Pitch ’n Time. When they are installed on your computer, those algorithms can be accessed from the same menu.

    You will now time stretch the My Rock Drums Loop region to make it exactly two bars long. To time stretch a region, hold down Option as you resize the region.

    Tip

    You can time stretch MIDI regions using the same technique.

    You may want to zoom in on the region before time stretching it.

  10. Position the mouse pointer over the lower-right corner of the My Rock Drums Loop region.

    Tip

    The mouse pointer turns into a Resize pointer.

  11. Option-drag the Resize pointer toward the right until the help tag indicates a region length of two bars, 2 0 0 0.

    Tip

    As you Option-drag the Resize pointer, it snaps to the grid, making it easy to stretch the region to exactly two bars. The help tag indicates that you are stretching the region, and you can see the audio waveform inside the region being stretched.

    When you release the mouse button, an alert message appears asking you to confirm the operation.

    Tip
  12. Click OK (or press Enter).

    Tip

    Another alert message appears, asking for confirmation that you want to destructively time stretch the audio file My Rock Drums Loop.1.aif. Look at the Audio Bin. Logic automatically duplicated the original audio file, and appended .1 to the copy’s filename. Time stretching is a destructive operation, so Logic will perform the time stretch on the copy, leaving the original file unaltered.

    Tip
  13. Click Process (or press Enter).

    Tip

    At the top of the Arrange area, a help tag appears displaying the number of samples being processed.

    When the processing is completed, the region in the Arrange area is replaced with the time-stretched copy, My Rock Drums Loop.1.

  14. Position the mouse pointer at the upper right of My Rock Drums Loop.1 to get the Loop tool and drag out two repeats to fill the last section of the song.

    Tip
  15. Position the playhead before the last section and start playback.

    The My Rock Drums Loop.1 region now perfectly matches the tempo of the project.

    Listen to the last section. The new drum loop is a good fit for the song, but at the moment, it is overpowering the original drum beat and the other instruments. You can mix it with the song so that it blends better.

    The High Pitch Synth on track 8 is panned to the left, so you will pan the loop to the right to balance it with the synth.

  16. Make sure the Audio 6 track containing the new drum loop is selected, and drag its balance knob up to about +20.

    Tip

    The drum loop is positioned to the right, leaving the center space available to place the other instruments, which no longer sound as though they are buried underneath the drum loop.

    Now you will use a channel strip setting to give that loop some texture.

  17. At the top of the Audio 6 Channel Strip, click the Setting button, and choose 02 Electric Guitar > 06 Distorted (Effects) > Distorted – Filter > Pig Wah.

    That creates too much distortion, and the drum loop is much too loud. Also, the wah effect is a little exaggerated. You should bypass the Fuzz-Wah plug-in.

  18. Option-click the Fuzz-Wah plug-in.

    Tip

    The plug-in is bypassed.

  19. Drag down the Audio 6 channel strip volume fader to about –6 (dB).

    Position the playhead around bar 13 and listen to the end section. Now the new drum loop adds an interesting texture to the section without blurring the other instruments.

To put your new time-stretching skills to work, try time stretching the reversed hi-hat on track 7 to lengthen it two to three times. Then open it in the Sample Editor and readjust the anchor position to its maximum amplitude peak, as you did in Lesson 3. A longer reversed hi-hat sample will build up even more tension to announce the ending of the song.

You now have a large repertoire of techniques to ensure that any audio file recorded or imported in a project will play back at the project tempo. Mastering these techniques will give you the freedom to use almost any pre-recorded material in your projects, so keep your ears out for interesting material you hear that you think could be sampled and looped for one of your future songs.

Lesson Review

1.

In the Loop Browser, how do you customize a category button?

2.

How can you change a project’s key signature?

3.

How do you match the project tempo to an audio file’s tempo?

4.

How do you time stretch a MIDI or an audio region?

5.

How do you make an audio region follow the tempo of the project?

6.

How do you insert tempo changes?

7.

Which region types will always follow the project’s tempo map?

8.

How do you create an Apple Loops file from a region?

9.

What are Apple Loops? Describe the difference between blue and green Apple Loops.

Answers

1.

Control-click the button and choose another category.

2.

Open the global tracks, and double-click the key signature on the global Signature track. Choose a new key from the Key Signature window.

3.

Drag a cycle of the same number of bars as the audio file. Then, in the main menu, choose Options > Tempo > Adjust Tempo using Region Length and Locators.

4.

Press Option as you resize the region.

5.

In the Inspector’s Region Parameter box, select Follow Tempo.

6.

In the global Tempo track, double-click above or below the tempo line.

7.

MIDI regions, Apple Loops, and audio regions set to follow tempo.

8.

Select the region and, in the Arrange area’s local menu bar, choose Region > Add to Apple Loops Library.

9.

Apple Loops are AIFF or CAF audio files that automatically match the project’s tempo and key. Unlike blue Apple Loops, green Apple Loops also contain the MIDI region and software instrument channel strips used to create them, and they can be used on software instrument tracks.

..................Content has been hidden....................

You can't read the all page of ebook, please click here login for view all page.
Reset
44.210.99.209