Setting a Project Tempo by Detecting the Tempo of a Recording

While listening to various recordings, you’ve found a recording of drums you like because of the way it grooves at its original tempo. To build a project around it, you need to adjust the project’s tempo to match the recording. When the two tempos match, you can use the grid to edit and quantize regions, or add Apple Loops and keep everything synchronized.

In this exercise, you will import a drums recording into a new project, let Logic detect the tempo of the drums, and set it as the project tempo.

1. Choose File > New, or press Shift-Command-N, and create one audio track.

   You will now set up Smart Tempo so that Logic detects the tempo of the audio file that you import and sets the project tempo accordingly.

2. Click the Project Tempo pop-up menu, and choose ADAPT–Adapt Project Tempo.

   

   The global tempo track opens so you can easily spot any tempo changes that Logic may create. The tempo curve is orange, and in the LCD display, the project tempo and time signature are also orange, indicating that those parameters are ready to adapt to the audio file you’re about to import.

3. In the control bar, click the Browsers button, or press F, and click the All Files tab.

4. Navigate to Logic Book Projects > Media, and drag Slow Drums.aif to bar 1 on the audio track.

   

   An alert asks if you want to open the Smart Tempo Editor, which will allow you to refine Logic’s tempo detection. Let’s open it.

   Note ▶

   If Logic has previously analyzed this audio file (for example, if you’ve already done this lesson), this alert won’t appear. To remove the analysis information embedded in the audio file, choose Edit > Tempo > Remove Original Recording Tempo from Audio File.

5. Click Show.

   

   The Smart Tempo Editor opens at the bottom of the main window. In the global tempo track, three tempo changes are created at bar 1, bar 2, and bar 26, beat 3 (at the end of the Audio region). Logic shows rounded tempo values of 123 bpm.

   Note ▶

   To see the exact tempo value of a section, click the arrow button at the lower right of the LCD display and choose Custom. Then locate the playhead in the desired section.

6. In the control bar, click the Metronome button (or press K).

7. Listen to the song.

   The drums are in sync with the metronome; however, they actually play at half the speed. You can correct this in the Smart Tempo Editor.

8. In Smart Tempo Editor, click the /2 button.

   

   The global tempo track now displays both tempo changes’ rounded values as 61.5.

9. Listen to the song. Now the drums are perfectly in sync with the metronome.

10. In the control bar, click the Editors button (or press E) to close the Smart Tempo Editor.

    

11. In the LCD display, click the Project Tempo mode, and choose KEEP–Keep Project Tempo.

    

12. Click the Metronome button, or press K, to turn the metronome off.

13. Choose File > Save (or press Command-S); in the Save dialog, choose a name and a location for your project, and then press Return.

Now that you’ve set the project tempo to match the drums tempo, you can add Apple Loops, and they will automatically match the tempo of your drums. You can also use the grid in the workspace to cut an exact numbers of bars in a region, which you’ll need later in this lesson to cut a drum loop.

Matching an Audio File to the Project Key and Tempo

Many current music genres find inspiration in older music, and it’s common for producers to use samples of older recordings, whether for a vocal part or an orchestra hit. Recycling existing material to use in a new song can present a challenge when the existing material has rhythmic and melodic or harmonic content. You have to make sure that the sampled recording plays at the current project’s key signature and tempo.

Smart Tempo allows you to automatically match the tempo of an imported audio file to the project tempo, and the Transpose parameter in the Region inspector makes it a breeze to change the pitch of that imported file.

1. Choose File > Project Settings > Smart Tempo.

   You will make this project turn on the Flex & Follow region parameter for imported audio files so that they sync up to the project tempo.

2. Click the “Set imported audio files to” pop-up menu, and choose On. Close the Settings window.

   

   Logic will analyze any audio file you import to detect its original tempo, and time-stretch it, as necessary, to make it play back at the project tempo. Let’s import a guitar part.

3. In the control bar, click the Browsers button, and in the Browser pane, click the All Files tab.

4. Navigate to Logic Book Projects > Media.

   Before importing Groovy Guitar.wav, let’s try to play it along with the project.

5. In the control bar, click the Play button to play the project.

6. In the All Files Browser, click Groovy Guitar.wav to preview it.

   It’s pretty obvious that the guitar wasn’t recorded in the same key or at the same tempo as the current project.

7. Drag Groovy Guitar below the bass track at bar 1.

   

   A progress bar appears while Logic analyzes the file, and then an alert asks if you want to show the Smart Tempo Editor, which allows you to perform more advanced tasks, such as editing the beats detected by Logic in the imported audio file. You won’t need to perform such tasks for this exercise.

8. Click Don’t Show to dismiss the alert.

   Note ▶

   If the region snaps to another position, drag it left to make sure it starts exactly on 1 1 1 1.

9. Play the project from the beginning.

   The guitar plays at the right tempo, but in the wrong key! You will fix that later, but for now, let’s focus on the timing of the guitar.

10. In the bass track header (Track 2), click the Mute (M) button to mute the track.

    

11. Listen to the project.

    The guitar and the drums play in time. Now, let’s make the guitar play in the right key. The guitar was recorded in D minor, and the current project’s key signature is E minor, so you need to transpose the guitar two semitones up.

12. Make sure the Groovy Guitar region is selected, and in the Region inspector, double-click to the right of the Transpose parameter.

    

13. Enter 2, and press Return.

    

    The amount of transposition is indicated to the right of the region name (+2).

14. Unmute the bass track (Track 2).

15. Listen to the project.

    The guitar now plays at both the correct tempo and key signature. It still ends too early, and in the following exercise, you will take care of copying the guitar a few times to make sure it fills up the Groovy Guitar track.

16. Choose File > Save (or press Command-S) to save your project.

Creating Tempo Changes and Tempo Curves

When you want to vary the tempo throughout a project, you can use the Tempo track to insert tempo changes and tempo curves. All MIDI regions and Apple Loops automatically follow the project tempo, even when tempo variations occur in the middle of a region. The Groovy Guitar is not an Apple Loop, but earlier you chose to turn on Flex and Follow Tempo for imported audio files, so that region will also follow the project’s tempo curve.

Making One Track Follow the Groove of Another Track

Playing all tracks at the same tempo is not always sufficient to achieve a tight rhythm. You also need to make sure they play with the same groove. For example, a musician may play slightly late to create a laid-back feel, or they may add some swing to their performance by delaying only the upbeats. On another track, notes may be placed on a rigid grid.

To learn how to get your tracks in the same groove, you will open a new project with a drummer playing a swing groove, and then make a shaker on another track follow the groove of the drummer.

1. Open Logic Book Projects > 09 Swing Groove, and listen to the song.

   Even though both tracks play at the same tempo, they are not synchronized. The drums (Track 1) are playing a hip-hop shuffle groove, whereas the shaker is playing on a straight sixteenth-note grid. Feel free to solo the individual tracks to clearly hear each instrument’s feel.

   Let’s zoom in so that you can see the individual drum hits on the waveforms.

2. Press Return to go back to the beginning of the project.

3. Press Command-Right Arrow nine times to zoom in on the first two beats (so you can see 1 and 1.2 in the ruler).

   

   Below the 1.2 grid mark in the ruler, you can clearly see that the waveforms on the two tracks are out of sync.

   To make the shaker follow the groove of the drums, you need to set the Drums track as the groove track.

4. Control-click a track header, and from the shortcut menu, choose Track Header Component > Groove Track.

   At first glance, nothing seems to have changed in the track headers.

5. Position the pointer over the track number (1) of the Drums track.

   

   A gold star appears in place of the track number.

6. Click the gold star.

   

   The gold star appears in a new column on the track header to indicate that the Drums track is now the groove track. On the Shaker track header, in the same column, you can select the checkbox to make that track follow the groove track.

7. On the Shaker track, select the Match Groove Track checkbox.

   

   The waveform on the Shaker track updates so that the notes are in sync with the notes on the groove track.

8. Listen to the song. The shaker now follows the groove of the drums, and they play in sync.

9. Solo the Shaker track.

10. While listening to the shaker, deselect and select the Match Groove Track checkbox to compare the original performance with the new groove.

    When the checkbox is unselected, the shaker plays straight eighth notes and sixteenth notes.

    When the checkbox is selected, the shaker plays the same hip-hop shuffle feel as the drums.

11. Unsolo the Shaker track.

12. Choose File > Close Project without saving the project.

Groove tracks work with all track types (Audio, Software Instrument, and Drummer tracks). Experiment by applying the groove of a sample to your MIDI programming or by making a Drummer track follow the groove of a live bass recording.

Changing the Playback Pitch and Speed with Varispeed

In the days of analog tape recording, engineers performed all sorts of tricks by changing the tape speed. Many major albums were sped up ever so slightly during the mixing process to add excitement to tracks by raising their tempos. This simultaneously raised the pitch, giving the impression of the vocalist reaching higher notes in the most emotional passages of the song. On the other hand, engineers would sometimes slow the tape during recording so that a musician could play a challenging passage at a more comfortable tempo. When played back at its regular speed during mixdown, the recording created the illusion of the musician playing faster. DJs are probably the biggest users of Varispeed techniques, which gives them control over the tempo and pitch of a track, allowing for seamless transitions from one track to the next.

Logic takes this concept a step further, offering both the classic Varispeed—which, like a tape or record player, changes both the pitch and the speed—and a Speed Only mode, which allows you to change the speed without changing the pitch.

1. Open Logic Book Projects > 09 Moments (by Darude), and listen to the song.

   Most of the tracks in the song are packed inside track stacks. On the track headers, feel free to click the disclosure triangles to open the track stacks and peek inside. To explore deeper, you can press Control-S to turn on Solo mode and click different tracks or subtracks to hear them in isolation and become familiar with this song.

   In the LCD display in the control bar, you can see that the song is in the key of G minor and its tempo is 128 bpm. To use the Varispeed feature, you must add the Varispeed display to the control bar.

2. Control-click an empty space in the control bar, and from the shortcut menu, choose Customize Control Bar and Display.

   

   In the dialog’s LCD column, the Varispeed option is dimmed. To turn it on, you first need to choose the custom LCD display.

3. In the LCD column, from the pop-up menu, choose Custom.

   

4. Below the pop-up menu, select Varispeed, and click OK.

   

   A new Varispeed display appears in the custom LCD display.

   

5. In the Varispeed display, drag the 0.00% value down to –6.00%.

   

   The Varispeed display is shaded in orange. The tempo value turns orange, too, indicating that the song is no longer playing at its normal tempo due to the Varispeed feature. If your main window is wide enough to display all the buttons to the right of the LCD display, you’ll see the Varispeed button turn orange to indicate that the feature is enabled.

   

6. Listen to the song.

   The song plays slower but retains its original pitch. Let’s check the song’s current playback tempo.

7. In the Varispeed display, click the % symbol, and from the pop-up menu, choose Resulting Tempo.

   

   The Varispeed display shows the resulting tempo of 120.320 bpm. You can now use the display to set the desired playback tempo.

8. Double-click the 120.320 tempo value, and enter 118 bpm.

   

   The song plays slower but still at its original pitch. This would be perfect for practicing a part by playing along with your instrument. You could even record your part at this speed, and then turn off Varispeed to play the whole song (including your newly recorded part) at the normal speed.

   Now let’s apply the classic Varispeed effect that changes both the playback speed and pitch.

9. In the Varispeed display, click Speed Only, and from the pop-up menu, choose Varispeed.

   

10. Listen to the song.

    Now the song plays both slower and lower in pitch. This is the classic Varispeed effect available on tape machines and turntables.

11. In the Varispeed display, click the bpm symbol, and from the pop-up menu, choose Detune (Semitones.Cents).

12. Double-click the –1.41 detune value, and enter –2.00.

    

13. Listen to the song.

    Now the song plays slower and pitched down by one semitone. If your singer isn’t at the top of their game that day and can’t reach their usual high notes, you could record at this slower speed and later turn off Varispeed to play the whole song at the higher pitch.

14. In the control bar, click the Varispeed button to turn it off.

    

    In the LCD display, the Varispeed display is no longer orange, indicating it’s been turned off, and the project plays at its original speed and pitch.

Editing the Timing of an Audio Region

In Logic, Flex Time is a tool that allows you to edit the timing of individual notes, chords, drum hits, or even smaller portions of audio inside an Audio region. When using Flex Time, the audio is first analyzed to locate transients (the attacks of individual notes), and Logic positions transient markers on top of the waveform. You can then create Flex markers and drag them to change the positions of the transients, and determine how the audio material around the markers is moved, time-stretched, or time-compressed.

Tuning Vocal Recordings

Hitting pitches perfectly on every single note can be a challenge for singers. Tuning software allows you to correct pitches in a recording. It can be useful for saving an emotional take that contains a few off-pitch notes, or even to refine the pitch of a good performance.

In Logic, Flex Pitch allows you to precisely edit the pitch curve of a single note, along with the amount of vibrato. In this exercise, you will use Flex Pitch to tune the vocals in the pink regions on the Ad Lib track (Track 27).

1. On the Ad Lib track (Track 27), click the pink Ad Lib 2 region in the CHORUS 2 section to select it.

2. Press Z.

   The selected region fills the workspace.

3. Choose Navigate > Set Locators by Selection and Enable Cycle (or press Command-U).

   

4. In the Ad Lib track header, click the Solo button (or select the track and press S).

   From now on, you can press the Space bar to toggle playback on and off.

5. In the Ad Lib track header, click the Track Flex button.

   Flex is turned on for that track, and transient markers appear over the waveform. Logic automatically selects the Polyphonic (Auto) mode; however, to tune the pitch, you’ll use the Flex Pitch mode.

6. In the track header, click the Flex Mode pop-up menu and choose Flex Pitch.

   

   As in the Piano Roll Editor, the note pitches are represented as beams on a grid. (You may need to scroll up or down to see the note beams.) On the grid, light-gray lanes correspond to the white keys on the piano keyboard, and dark-gray lanes correspond to the black keys. The section of a note beam that intersects with the closest lane is colored, and the height of the hollowed-out section of the beam represents the amount of deviation from the perfect pitch. When a note plays at the perfect pitch, it sits exactly on a lane, and the beam doesn’t have any hollowed-out section.

7. Click the second note to select it.

   

   On top of the frame, a light-gray line represents the pitch curve so that you can see pitch drifts and vibrato.

8. Listen to the vocals.

   The singer sings “moments just like this,” alternating between G and F notes. There are a few problems with the singer’s pitch that you will correct. The selected note is the beginning of the word “moments,” and it sounds sharp.

9. Control-click the beam, and from the shortcut menu, choose Set to Perfect Pitch.

   

   The beam snaps to the closest lane, and the entire beam is colored, indicating that the note plays at the perfect pitch.

   

   The next note is the end of the word “moments,” and it also sounds sharp; however, it’s so sharp that Logic detected it as an F#. Let’s try to correct it.

10. Control-click the beam of the following note, and choose Set to Perfect Pitch.

    

    Tip

    To quickly tune an entire region, Control-click the background and choose “Set all to Perfect Pitch.”

    The beams snaps to an F#. The “ments” end part of the word “moments” now sounds exactly one semitone sharp: It should be an F. To transpose it, you can simply drag it vertically as you would drag a note in the Piano Roll.

11. Drag the F# note to an F.

    

    While you hold down the mouse button, you can hear the pitch of the audio signal at the exact horizontal position you clicked in the pitch curve.

    The word “moments” now goes from a G to an F and the pitch sounds perfect. The next note, the word “just,” a G, is flat.

12. Control-click the next note and choose Set to Perfect Pitch.

    

    The pitch of “just” now sounds the same as the beginning of the word “moments”—perfect.

    The next two beams represent the word “like”; however, the first one is only there because the singer ramps up into the right pitch at the beginning of the word. So you’ll leave it alone, tuning only the next beam, which represents the vowel part of the word “like.”

13. Control-click the second beam of the word “like,” and choose Set to Perfect Pitch.

    

    The beam snaps to a G, which is the correct pitch for that note; however, it still sounds a little sharp. Look at the pitch curve: The beginning of the “i” vowel in “like” goes up too high. Let’s tame that.

    As you position the pointer in the vicinity of the colored beam, hotspots appear around the beam that allow you to perform various adjustments.

    

    Note ▶

    Sometimes, pitch correction can alter the timbre of a sound, especially when you play a note several semitones away from its original pitch. At some point, pitching up a vocal makes the singer sound like a chipmunk, whereas pitching it down makes the singer sound like a hulking monster. Dragging the Formant hotspot up or down helps you adjust the timbre to make it sound more realistic.

14. Drag the lower-mid hotspot to set Vibrato to 0%.

    

    Tip

    To adjust a parameter on multiple notes, select the desired beams (or press Command-A to select them all) and adjust the parameters on one of the selected beams.

    The pitch curve of that note is flatlined, and the pitch now sounds perfect. Let’s try to flatten the pitch curve of the last sustained note on the word “this.”

15. On the last note in the region, drag the lower-mid hotspot to set Vibrato 0%.

    

    The pitch is perfect, but it sounds unnatural, almost synth-like. Even for a dance music production, that effect is a bit over the top.

16. Drag the lower-mid hotspot to set the Vibrato to 50% to halve the pitch deviations around the perfect pitch. Feel free to continue adjusting the pitch of the notes in other regions on the Ad Lib track. Don’t be afraid to experiment with the other hotspots (pitch drift, fine pitch, gain and formant pitch), and if you’re not happy with a result, choose Edit > Undo (or press Command-Z).

    

You now have a large repertoire of techniques that you can use to edit the tempo of a project and the timing of its regions, and you can make a track follow the groove of another track. Mastering these techniques will give you the freedom to use almost any prerecorded material in your projects, so keep your ears tuned to interesting material that you could sample and loop for your future songs.

Flex Time and Flex Pitch editing can help you correct imperfections in a performance, bringing your material to a new level of precision. Using Varispeed, tempo curves, groove tracks, and Flex Time and Flex Pitch editing techniques, you have a full palette of special effects that can add ear candy to your productions.

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