Appendix A: MIDI Constants

A.1 Overview

To simplify your coding, the Python Music Library defines many musical constants for you. These constants (words and abbreviations) can be used in place of numbers in your code. In many cases, each value is represented by several alternate constants (words). For example, the rhythm value 1.0 is equivalent to the constants QUARTER_NOTE and QN.

Notice that most of the constants are in upper case, which makes them easier to recognize in Python code. Python is a case-sensitive language, which means that these constants must be written using the case that appears here. Their numerical values are shown here, but you can also find them easily by typing the constants in the interpreter.

You should use these constants whenever possible instead of the actual (literal) values, for two reasons*:

1. To improve the readability of your programs
2. To ensure that your programs continue working as intended, in case some of these values change in subsequent releases of the music library (unlikely, but possible).

This is an important rule to remember.

A.2 Pitch Constants

Note pitches are represented as in the MIDI specification, using integers from 0 (lowest pitch) to 127 (highest pitch). That’s a total of 128 pitches (i.e., 10 octaves). There is some disagreement on how to number these octaves. A common way is to number the highest octave as 9, the second to lowest octave as 0, and the lowest octave as −1.

The music library defines the following pitch constants for convenience. For example, the highest possible pitch is G9; it is equal to 127. The lowest possible note is C_1 (C negative one); it is equal to 0. Use these constants whenever possible. They improve the readability of the code.

Additionally, there is a special pitch corresponding to rests. A rest is a note whose pitch is:

REST

Rests are notes that last as long as you specify (see rhythm value constants), but produce no sound.

Here are the regular pitch constants in decreasing pitch value:

G9 = 127, GF9 = 126, FS9 = 126, F9 = 125, FF9 = 124, ES9 = 125, E9 = 124, EF9 = 123, DS9 = 123, D9 = 122, DF9 = 121, CS9 = 121, C9 = 120, CF9 = 119, BS8 = 120, B8 = 119, BF8 = 118, AS8 = 118, A8 = 117, AF8 = 116, GS8 = 116, G8 = 115, GF8 = 114, FS8 = 114, F8 = 113, FF8 = 112, ES8 = 113, E8 = 112, EF8 = 111, DS8 = 111, D8 = 110, DF8 = 109, CS8 = 109, C8 = 108, CF8 = 107, BS7 = 108, B7 = 107, BF7 = 106, AS7 = 106, A7 = 105, AF7 = 104, GS7 = 104, G7 = 103, GF7 = 102, FS7 = 102, F7 = 101, FF7 = 100, ES7 = 101, E7 = 100, EF7 = 99, DS7 = 99, D7 = 98, DF7 = 97, CS7 = 97, C7 = 96, CF7 = 95, BS6 = 96, B6 = 95, BF6 = 94, AS6 = 94, A6 = 93, AF6 = 92, GS6 = 92, G6 = 91, GF6 = 90, FS6 = 90, F6 = 89, FF6 = 88, ES6 = 89, E6 = 88, EF6 = 87, DS6 = 87, D6 = 86, DF6 = 85, CS6 = 85, C6 = 84, CF6 = 83, BS5 = 84, B5 = 83, BF5 = 82, AS5 = 82, A5 = 81, AF5 = 80, GS5 = 80, G5 = 79, GF5 = 78, FS5 = 78, F5 = 77, FF5 = 76, ES5 = 77, E5 = 76, EF5 = 75, DS5 = 75, D5 = 74, DF5 = 73, CS5 = 73, C5 = 72, CF5 = 71, BS4 = 72, B4 = 71, BF4 = 70, AS4 = 70, A4 = 69, AF4 = 68, GS4 = 68, G4 = 67, GF4 = 66, FS4 = 66, F4 = 65, FF4 = 64, ES4 = 65, E4 = 64, EF4 = 63, DS4 = 63, D4 = 62, DF4 = 61, CS4 = 61, C4 = 60, CF4 = 59, BS3 = 60, B3 = 59, BF3 = 58, AS3 = 58, A3 = 57, AF3 = 56, GS3 = 56, G3 = 55, GF3 = 54, FS3 = 54, F3 = 53, FF3 = 52, ES3 = 53, E3 = 52, EF3 = 51, DS3 = 51, D3 = 50, DF3 = 49, CS3 = 49, C3 = 48, CF3 = 47, BS2 = 48, B2 = 47, BF2 = 46, AS2 = 46, A2 = 45, AF2 = 44, GS2 = 44, G2 = 43, GF2 = 42, FS2 = 42, F2 = 41, FF2 = 40, ES2 = 41, E2 = 40, EF2 = 39, DS2 = 39, D2 = 38, DF2 = 37, CS2 = 37, C2 = 36, CF2 = 35, BS1 = 36, B1 = 35, BF1 = 34, AS1 = 34, A1 = 33, AF1 = 32, GS1 = 32, G1 = 31, GF1 = 30, FS1 = 30, F1 = 29, FF1 = 28, ES1 = 29, E1 = 28, EF1 = 27, DS1 = 27, D1 = 26, DF1 = 25, CS1 = 25, C1 = 24, CF1 = 23, BS0 = 24, B0 = 23, BF0 = 22, AS0 = 22, A0 = 21, AF0 = 20, GS0 = 20, G0 = 19, GF0 = 18, FS0 = 18, F0 = 17, FF0 = 16, ES0 = 17, E0 = 16, EF0 = 15, DS0 = 15, D0 = 14, DF0 = 13, CS0 = 13, C0 = 12, CF0 = 11, BS_1 = 12, B_1 = 11, BF_1 = 10, AS_1 = 10, A_1 = 9, AF_1 = 8, GS_1 = 8, G_1 = 7, GF_1 = 6, FS_1 = 6, F_1 = 5, FF_1 = 4, ES_1 = 5, E_1 = 4, EF_1 = 3, DS_1 = 3, D_1 = 2, DF_1 = 1, CS_1 = 1, C_1 = 0

A.3 Rhythm Value Constants

Note durations are represented using real numbers (floats). For example, 4.0 stands for a whole note, 2.0 for a half note, 1.0 for a quarter note, and so on. The music library defines constants for common duration values.

Here are the common durations in decreasing duration value:

WHOLE_NOTE, WN = 4.0

DOTTED_HALF_NOTE, DHN = 3.0

DOUBLE_DOTTED_HALF_NOTE, DDHN = 3.5

HALF_NOTE, HN = 2.0

HALF_NOTE_TRIPLET, HNT = 4.0/3.0

QUARTER_NOTE, QN = 1.0

QUARTER_NOTE_TRIPLET, QNT = 2.0/3.0

DOTTED_QUARTER_NOTE, DQN = 1.5

DOUBLE_DOTTED_QUARTER_NOTE, DDQN = 1.75

EIGHTH_NOTE, EN = 0.5

DOTTED_EIGHTH_NOTE, DEN = 0.75

EIGHTH_NOTE_TRIPLET, ENT = 1.0/3.0

DOUBLE_DOTTED_EIGHTH_NOTE, DDEN = 0.875

SIXTEENTH_NOTE, SN = 0.25

DOTTED_SIXTEENTH_NOTE, DSN = 0.375

SIXTEENTH_NOTE_TRIPLET, SNT = 1.0/6.0

THIRTYSECOND_NOTE, TN = 0.125

THIRTYSECOND_NOTE_TRIPLET, TNT = 1.0/12.0

A.4 Dynamic Constants

Dynamic or volume of notes (also known as MIDI velocity) is represented as in the MIDI specification using integers from 0 (silent) to 127 (loudest). That’s a total of 128 volume settings. The music library defines the following dynamic constants for convenience.

Here are the dynamic constants in decreasing loudness value:

FFF = 120

FORTISSIMO, FF = 100

FORTE, F = 85

MEZZO_FORTE, MF = 70

MEZZO_PIANO, MP = 60

P = 50

PIANISSIMO, PP = 25

PPP = 10

SILENT = 0

A.5 Panning Constants

Panning (or panoramic) constants are represented in the music library using real numbers (floats) from 0.0 (left) to 1.0 (right). Given that human ears are very sensitive to placement of sound in a stereo field, using floats allows for much greater detail than the following constants allow:

Here are the panning constants in increasing value:

PAN_LEFT = 0.0

PAN_CENTER = 0.5

PAN_RIGHT = 1.0

A.6 General MIDI Instrument Constants

Instruments (timbre options) (also known as MIDI program changes) are represented as in the MIDI specification using integers from 0 to 127. That’s a total of 128 timbre settings. The music library defines the following instrument constants for convenience.

Below are the instrument constants in increasing value (and grouped in terms of instrument family).

A.6.1 Piano Family

ACOUSTIC_GRAND, PIANO = 0

BRIGHT_ACOUSTIC = 1

ELECTRIC_GRAND = 2

HONKYTONK_PIANO, HONKYTONK = 3

EPIANO1, RHODES_PIANO, RHODES = 4

EPIANO2, DX_PIANO, DX = 5

HARPSICHORD = 6

CLAVINET = 7

A.6.2 Pitched Percussion Family

CELESTA = 8

GLOCKENSPIEL = 9

MUSIC_BOX = 10

VIBRAPHONE, VIBES = 11

MARIMBA = 12

XYLOPHONE = 13

TUBULAR_BELLS = 14

DULCIMER = 15

A.6.3 Organ Family

DRAWBAR_ORGAN, ORGAN = 16

PERCUSSIVE_ORGAN, JAZZ_ORGAN = 17

ROCK_ORGAN = 18

CHURCH_ORGAN = 19

REED_ORGAN = 20

ACCORDION = 21

HARMONICA = 22

TANGO_ACCORDION, BANDONEON = 23

A.6.4 Guitar Family

NYLON_GUITAR, GUITAR = 24

STEEL_GUITAR = 25

JAZZ_GUITAR = 26

CLEAN_GUITAR, ELECTRIC_GUITAR = 27

MUTED_GUITAR = 28

OVERDRIVEN_GUITAR = 29

DISTORTION_GUITAR = 30

GUITAR_HARMONICS = 31

A.6.5 Bass Family

ACOUSTIC_BASS = 32

BASS, ELECTRIC_BASS, FINGERED_BASS = 33

PICKED_BASS = 34

FRETLESS_BASS = 35

SLAP_BASS1 = 36

SLAP_BASS2 = 37

SYNTH_BASS1 = 38

SYNTH_BASS2 = 39

A.6.6 Strings and Timpani Family

VIOLIN = 40

VIOLA = 41

CELLO = 42

CONTRABASS = 43

TREMOLO_STRINGS = 44

PIZZICATO_STRINGS = 45

ORCHESTRAL_HARP, HARP = 46

TIMPANI = 47

A.6.7 Ensemble Family

STRING_ENSEMBLE1, STRINGS = 48

STRING_ENSEMBLE2 = 49

SYNTH_STRINGS1, SYNTH = 50

SYNTH_STRINGS2 = 51

CHOIR_AHHS, CHOIR = 52

VOICE_OOHS, VOICE = 53

SYNTH_VOICE, VOX = 54

ORCHESTRA_HIT = 55

A.6.8 Brass Family

TRUMPET = 56

TROMBONE = 57

TUBA = 58

MUTED_TRUMPET = 59

FRENCH_HORN, HORN = 60

BRASS_SECTION, BRASS = 61

SYNTH_BRASS1 = 62

SYNTH_BRASS2 = 62

A.6.9 Reed Family

SOPRANO_SAX, SOPRANO_SAXOPHONE = 64

ALTO_SAX, ALTO_SAXOPHONE = 65

TENOR_SAX, TENOR_SAXOPHONE, SAX, SAXOPHONE = 66

BARITONE_SAX, BARITONE_SAXOPHONE = 67

OBOE = 68

ENGLISH_HORN = 69

BASSOON = 70

CLARINET = 71

A.6.10 Pipe Family

PICCOLO = 72

FLUTE = 73

RECORDER = 74

PAN_FLUTE = 75

BLOWN_BOTTLE, BOTTLE = 76

SHAKUHACHI = 77

WHISTLE = 78

OCARINA = 79

A.6.11 Synth Lead Family

LEAD_1_SQUARE, SQUARE = 80

LEAD_2_SAWTOOTH, SAWTOOTH = 81

LEAD_3_CALLIOPE, CALLIOPE = 82

LEAD_4_CHIFF, CHIFF = 83

LEAD_5_CHARANG, CHARANG = 84

LEAD_6_VOICE, SOLO_VOX = 85

LEAD_7_FIFTHS, FIFTHS = 86

LEAD_8_BASS_LEAD, BASS_LEAD = 87

A.6.12 Synth Pad Family

PAD_1_NEW_AGE, NEW_AGE = 88

PAD_2_WARM, WARM_PAD = 89

PAD_3_POLYSYNTH, POLYSYNTH = 90

PAD_4_CHOIR, SPACE_VOICE = 91

PAD_5_GLASS, BOWED_GLASS = 92

PAD_6_METTALIC, METALLIC = 93

PAD_7_HALO, HALO = 94

PAD_8_SWEEP, SWEEP = 95

A.6.13 Synth Effects Family

FX_1_RAIN, ICE_RAIN = 96

FX_2_SOUNDTRACK, SOUNDTRACK = 97

FX_3_CRYSTAL, CRYSTAL = 98

FX_4_ATMOSPHERE, ATMOSPHERE = 99

FX_5_BRIGHTNESS, BRIGHTNESS = 100

FX_6_GOBLINS, GOBLINS = 101

FX_7_ECHOES, ECHO_DROPS = 102

FX_8_SCI_FI, SCI_FI = 103

A.6.14 Ethnic Family

SITAR = 104

BANJO = 105

SHAMISEN = 106

KOTO = 107

KALIMBA = 108

BAGPIPE = 109

FIDDLE = 110

SHANNAI = 111

A.6.15 Percussive Family

TINKLE_BELL, BELL = 112

AGOGO = 113

STEEL_DRUMS = 114

WOODBLOCK = 115

TAIKO_DRUM, TAIKO = 116

MELODIC_TOM, TOM_TOM = 117

SYNTH_DRUM = 118

REVERSE_CYMBAL = 119

A.6.16 Sound Effects Family

GUITAR_FRET_NOISE, FRET_NOISE = 120

BREATH_NOISE, BREATH = 121

SEASHORE, SEA = 122

BIRD_TWEET, BIRD = 123

TELEPHONE_RING, TELEPHONE = 124

HELICOPTER = 125

APPLAUSE = 126

GUNSHOT = 127

A.7 General MIDI Drum and Percussion Constants

In addition to the above MIDI instruments, when using MIDI channel 9 (the MIDI protocol has 16 channels, numbered 0–15), each pitch corresponds to a different drum sound. The music library defines the following drum sound constants for convenience.

Here are the drum sound constants in increasing value:

ACOUSTIC_BASS_DRUM, ABD = 35

BASS_DRUM, BDR = 36

SIDE_STICK, STK = 37

SNARE, SNR = 38

HAND_CLAP, CLP = 39

ELECTRIC_SNARE, ESN = 40

LOW_FLOOR_TOM, LFT = 41

CLOSED_HI_HAT, CHH = 42

HIGH_FLOOR_TOM, HFT = 43

PEDAL_HI_HAT, PHH = 44

LOW_TOM, LTM = 45

OPEN_HI_HAT, OHH = 46

LOW_MID_TOM, LMT = 47

HI_MID_TOM, HMT = 48

CRASH_CYMBAL_1, CC1 = 49

HIGH_TOM, HGT = 50

RIDE_CYMBAL_1, RC1 = 51

CHINESE_CYMBAL, CCM = 52

RIDE_BELL, RBL = 53

TAMBOURINE, TMB = 54

SPLASH_CYMBAL, SCM = 55

COWBELL, CBL = 56

CRASH_CYMBAL_2, CC2 = 57

VIBRASLAP, VSP = 58

RIDE_CYMBAL_2, RC2 = 59

HI_BONGO, HBG = 60

LOW_BONGO, LBG = 61

MUTE_HI_CONGA, MHC = 62

OPEN_HI_CONGA, OHC = 63

LOW_CONGA, LCG = 64

HIGH_TIMBALE, HTI = 65

LOW_TIMBALE, LTI = 66

HIGH_AGOGO, HAG = 67

LOW_AGOGO, LAG = 68

CABASA, CBS = 69

MARACAS, MRC = 70

SHORT_WHISTLE, SWH = 71

LONG_WHISTLE, LWH = 72

SHORT_GUIRO, SGU = 73

LONG_GUIRO, LGU = 74

CLAVES, CLA = 75

HI_WOOD_BLOCK, HWB = 76

LOW_WOOD_BLOCK, LWB = 77

MUTE_CUICA, MCU = 78

OPEN_CUICA, OCU = 79

MUTE_TRIANGLE, MTR = 80

OPEN_TRIANGLE, OTR = 81

A.8 Scale and Mode Constants

Scales in the music library are defined as pitch class sets (i.e., chromatic scale degrees within one octave). The first pitch class sets is often 0, denoting the starting (root) note. There is wisdom in this representation. It allows us to use any MIDI note (pitch) as the starting note offset. For example, the following piece of code outputs the pitches for a major scale starting at C4:

root = C4	# starting pitch

scale = MAJOR_SCALE # scale

# output the pitches in this scale

for interval in scale:

	print root+interval # add the interval to the root

Change the C4 to another pitch, or change MAJOR_SCALE to another scale, and you will get the actual pitches of any possible scale. This demonstrates the power, flexibility, and economy of the music library’s representation for scales.

Here are the music library scale definitions in alphabetical order:

AEOLIAN_SCALE = [0, 2, 3, 5, 7, 8, 10]

BLUES_SCALE = [0, 2, 3, 4, 5, 7, 9, 10, 11]

CHROMATIC_SCALE = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]

DIATONIC_MINOR_SCALE = [0, 2, 3, 5, 7, 8, 10]

DORIAN_SCALE = [0, 2, 3, 5, 7, 9, 10]

HARMONIC_MINOR_SCALE = [0, 2, 3, 5, 7, 8, 11]

LYDIAN_SCALE = [0, 2, 4, 6, 7, 9, 11]

MAJOR_SCALE = [0, 2, 4, 5, 7, 9, 11]

MELODIC_MINOR_SCALE = [0, 2, 3, 5, 7, 8, 9, 10, 11]

MINOR_SCALE = [0, 2, 3, 5, 7, 8, 10]

MIXOLYDIAN_SCALE = [0, 2, 4, 5, 7, 9, 10]

NATURAL_MINOR_SCALE = [0, 2, 3, 5, 7, 8, 10]

PENTATONIC_SCALE = [0, 2, 4, 7, 9]

TURKISH_SCALE = [0, 1, 3, 5, 7, 10, 11]

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