SOUND ch, inst, note[, len[, vel]]
PARAMETERS
ch

sound channel [0 to 2] 3 midi channels

inst midi insruments 0 to 127 see below INsruments

instrument number
General Midi (GM)" standard defines a list of 128 instruments that simplifies compatibility 0 to 127

note

  See below Note=Pitch

The pitch value determines the frequency of the note to be played. It goes from 0 to 127, with the middle C note being represented by the value of 60:

len

note duration, milliseconds [default: 1000]

Duration is the time the note is held. The smallest unit of time is the tick, which is equal to 100 nanoseconds or one ten-millionth of a second. There are 10,000 ticks in a millisecond. Duration Beats per minute See Below Len = Duration

note velocity [0 to 1 (default)] vel 0 = off 1 = on

                       VEL = VELOCITY

The velocity value normally goes from .0 to .99 covering the range from a practically inaudible note up to the maximum note level. It basically corresponds to the scale of nuances found in music notation, as follows (it is more indicative than exact value

Converted from Midi velocity chart
multipiled by O,00787
Midi Basic Engine
pppp=8 .06
ppp=20 .16
pp=31 .24
p=42 .33
mp=53 .42
mf=64 .50
f=80 .63
ff=96 .76
fff=112 .88
ffff=127 .99

In basic synthesizers, the velocity value is used only to determine the force with which the note is played, the only effect being a note that is louder or softer in volume.

In more sophisticated synthesizer, this value will also affect the sound quality. Indeed, on a real piano, hitting a note harder will not only affect its loudness but also the quality of the sound itself, the timber. This is practically the case with any real instrument.

                             NOTES = PITCH

pitch---The pitch value determines the frequency of the note to be played. It goes from 0 to 127, with the middle C note being represented by the value of 60:

Octave Number
Notes
C C# D D# E F F# G G# A A# B

   0           0	1	2	3	4	5	6	7	8	9	10	11
   
   1           12	13	14	15	16	17	18	19	20	21	22	23
   
   2           24	25	26	27	28	29	30	31	32	33	34	35
   
   3           36	37	38	39	40	41	42	43	44	45	46	47
   
   4           48	49	50	51	52	53	54	55	56	57	58	59
   
   5           60	61	62	63	64	65	66	67	68	69	70	7
   
   6           72	73	74	75	76	77	78	79	80	81	82	83
   
   7           84	85	86	87	88	89	90	91	92	93	94	95
   
   8           96	97	98	99	100	101	102	103	104	105	106	107
   
   9           108	109	110	111	112	113	114	115	116	117	118	119
   
  10           120	121	122	123	124	125	126	127

The value is represented in half steps, so that C# will be 61, D will be 62,...

To transpose a note one octave higher, add 12 to its pitch value. By using MIDI, transposition is very simple as it is done simply by adding or subtracting a fixed value.

Be cautious however about the range of MIDI notes that goes from 0 to 127. By adding for instance 4 octaves (+48) to a note of value 96, the total is 144, which is outside the range and may be truncated to 16 (144 - 128) so that a very low note will result.

Converting from the AY-3-8910 Programmable Sound Generator (PSG)

            Note	Period	Note	Period
              C	    3421	F#      2419
              C#	3228	G	    2283
              D	    3047	G#	    2155
              D#	2876	A	    2034
              E	    2715	A#	    1920
              F	    2562	B	    1892

The lower the period, the higher the note. In order to get a higher octave, just divide the period by two.

midi instruments
1-8 Piano
9-16 Chromatic Percussion
17-24 Organ
25-32 Guitar
33-40 Bass
41-48 Strings
49-56 Ensemble
57-64 Brass
65-72 Reed
73-80 Pipe
81-88 Synth Lead
89-96 Synth Pad
97-104 Synth Effects
105-112 Ethnic
113-120 Percussive
121-128 Sound Effects

                            INS = Insruments

General MIDI Level 1 Instrument Patch Map

Note: While GM1 does not define the actual characteristics of any sounds, the names in parentheses after each of the synth leads, pads, and sound effects are, in particular, intended only as guides).
PC# Instrument Name

Acoustic Grand Piano
Bright Acoustic Piano
Electric Grand Piano
Honky-tonk Piano
Electric Piano 1
Electric Piano 2
Harpsichord
Clavi
Celesta
Glockenspiel
Music Box
Vibraphone
Marimba
Xylophone
Tubular Bells
Dulcimer
Drawbar Organ
Percussive Organ
Rock Organ
Church Organ
Reed Organ
Accordion
Harmonica
Tango Accordion
Acoustic Guitar (nylon)
Acoustic Guitar (steel)
Electric Guitar (jazz)
Electric Guitar (clean)
Electric Guitar (muted)
Overdriven Guitar
Distortion Guitar
Guitar harmonics
Acoustic Bass
Electric Bass (finger)
Electric Bass (pick)
Fretless Bass
Slap Bass 1
Slap Bass 2
Synth Bass 1
Synth Bass 2
Violin
Viola
Cello
Contrabass
Tremolo Strings
Pizzicato Strings
Orchestral Harp
Timpani
String Ensemble 1
String Ensemble 2
SynthStrings 1
SynthStrings 2
Choir Aahs
Voice Oohs
Synth Voice
Orchestra Hit
Trumpet
Trombone
Tuba
Muted Trumpet
French Horn
Brass Section
SynthBrass 1
SynthBrass 2
Soprano Sax
Alto Sax
Tenor Sax
Baritone Sax
Oboe
English Horn
Bassoon
Clarinet
Piccolo
Flute
Recorder
Pan Flute
Blown Bottle
Shakuhachi
Whistle
Ocarina
Lead 1 (square)
Lead 2 (sawtooth)
Lead 3 (calliope)
Lead 4 (chiff)
Lead 5 (charang)
Lead 6 (voice)
Lead 7 (fifths)
Lead 8 (bass + lead)
Pad 1 (new age)
Pad 2 (warm)
Pad 3 (polysynth)
Pad 4 (choir)
Pad 5 (bowed)
Pad 6 (metallic)
Pad 7 (halo)
Pad 8 (sweep)
FX 1 (rain)
FX 2 (soundtrack)
FX 3 (crystal)
FX 4 (atmosphere)
FX 5 (brightness)
FX 6 (goblins)
FX 7 (echoes)
FX 8 (sci-fi)
Sitar
Banjo
Shamisen
Koto
Kalimba
Bag pipe
Fiddle
Shanai
Tinkle Bell
Agogo
Steel Drums
Woodblock
Taiko Drum
Melodic Tom
Synth Drum
Reverse Cymbal
Guitar Fret Noise
Breath Noise
Seashore
Bird Tweet
Telephone Ring
Helicopter
Applause

Gunshot

      LEN = DURATION

Duration calculator https://www.homestudiosimplified.com/p/reverbdelay-calculator.html

Understanding BPM to ms

To convert from BPM to ms we first need to determine how many ms are in a minute.

1 minute = 60 seconds = 60,000 milliseconds

Divide 60,000 by the BPM to get the duration of a single beat – a quarter note. If our BPM is 100 we can write:

Quarter note duration = 60,000 / 100 = 600 ms.

From here we can multiply or divide to find the duration of other notes. For example, a half note is twice the duration of a quarter note.

Half note duration = 600 ms x 2 = 1,200 ms

A sixteenth note is half as long as an eighth note, which is half as long as a quarter note.

Eighth note duration = 600 ms / 2 = 300 ms

Sixteenth note duration = 300 ms / 2 = 150 ms

You could also divide the duration of a quarter note by 4 to achieve the same result.

Sixteenth note duration = 600 ms / 4 = 150 ms

Calculating dotted notes and triplets works in the exact same way, except we multiply the answers by 1.5 for a dotted note and 0.6667 for a triplet.

Dotted quarter note duration = 600 ms x 1.5 = 900 ms

Duration of one third of a quarter note triplet = 600 ms x 0.6667 = 400 ms