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This page is read from MIDI Instrument Definitions, a Python library used in the author's other projects, in which every number is traced to a document its maker published. Its source is on GitHub.

Roland TR-707 MIDI implementation

The MIDI implementation of the Roland TR-707: what it answers to.

At a glance

Firmware
Not recorded.
MIDI channel
Any one of 1 to 16.
Modes
Pattern Playing Mode.
Step Writing Mode.
Tap Writing Mode.
Track Playing Mode.
Track Writing Mode.
Parts
Drum voices: on the base MIDI channel, taking notes, each note working what is listed for it below, as it leaves the factory, in Track Playing Mode only.
MIDI mode
Receives in 1 (omni on, poly) and sends in 3 (omni off, poly).
Voices
Not recorded.
Notes
Each note plays a drum of its own, listed below with the part that takes them.
Note range
Not recorded.
Velocity
Sent and received. Release velocity is ignored.
Aftertouch
None, sent or answered.
Pitch bend
Not recorded.
Program change
Not received or sent.
MIDI clock
Sent and received.
Start and stop
Sent and received.
Control change
None.
NRPN
None.
System exclusive
Supported.

Drum voices notes

The player assigns this part's notes, and these are the notes it has from the factory. Where more than one note works the same thing, the first is the one to send. The instrument itself sends one of two sets of notes for them, chosen by a setting of its own: Setting A or Setting B.

What it works Answers to Sends in Setting A Sends in Setting B
bass_drum_1 35, B1 35, B1 36, C2
bass_drum_2 36, C2 36, C2 37, C#2
rim_shot 37, C#2 37, C#2 43, G2
snare_drum_1 38, D2 38, D2 38, D2
hand_clap 39, D#2 39, D#2 45, A2
snare_drum_2 40, E2 40, E2 39, D#2
low_tom 41, F2
43, G2		 41, F2 40, E2
closed_hi_hat 42, F#2
44, G#2		 42, F#2 47, B2
mid_tom 45, A2
47, B2		 45, A2 41, F2
open_hi_hat 46, A#2 46, A#2 48, C3
high_tom 48, C3
50, D3		 48, C3 42, F#2
crash_cymbal 49, C#3 49, C#3 49, C#3
ride_cymbal 51, D#3 51, D#3 50, D3
tambourine 54, F#3 54, F#3 46, A#2
cowbell 56, G#3 56, G#3 44, G#2

Where these facts come from

Source documents

How they were read

A SCAN OF ROLAND'S OWN MANUAL, READ BY EYE. 58 pages, each one image and not a character of text, served by Roland from its US manual archive as TR-707 Owner’s Manual; the cover reads RHYTHM COMPOSER, TR-707 and Owner's Manual beside Roland's name and a MIDI badge, and the specifications open with "TR-707 RHYTHM COMPOSER" (manual p. 47). No quotation below can be checked by a machine, so a second reader checked every one against the rendered page.

THE MIDI IMPLEMENTATION IS A REDUCED LISTING, SO ITS NOTE NUMBERS WERE READ TWICE. Two pages near the end reproduce a dot-matrix listing so small that the scan leaves a 3, a 5, a 6, an 8 and a 9 hard to tell apart (manual pp. 55-56). Every note number in it is printed again at full size: the received ones in a keyboard diagram (manual p. 44), the sent ones in two more (manual p. 46), and the range in the chart (manual p. 50). Where a digit in a diagram is broken as well, the key's place on the keyboard settles it. The diagrams and the listing agree on every number.

NO CONTROLLER, NO PROGRAM CHANGE, NO BEND AND NO AFTERTOUCH. The chart crosses Control Change, Prog Change, Pitch Bender and both kinds of After Touch in both columns (manual p. 50). The implementation's tables agree: what is sent is notes, song position, song select, clock, start, continue, stop and system exclusive, and what is recognised is the same with two mode messages, OMNI OFF and OMNI ON, added (manual p. 55). So control_change and nrpn are both none, as checked absences. The two mode messages are controllers 124 and 125, which belong to the MIDI specification and are not parameters of this instrument, and an NRPN needs controllers 98, 99, 6 and 38, none of which is in either table.

THE MIDI CHAPTER NAMES FOUR KINDS OF MESSAGE, AND THREE OF THEM IN ONE MODE ONLY. "The TR-707 can transmit and receive the following MIDI messages." (manual p. 42): a key message for each voice, the track number as Song Select, the bar number as Song Position, and the synchronising signals. Then "The messages 1, 2 and 3 can be sent or received only in Track Play mode." (manual p. 42), which is the Track Playing Mode among the instrument's five (manual p. 8). By that sentence a note sent to a TR-707 that is writing a pattern does nothing. So the fifteen voices below are a part of that mode. The one other place the manual has the instrument take a note is the procedure that teaches a voice its key number, which the chapter begins in Track Writing mode and the operation table in Track Playing mode: see below. The implementation says the same of notes, "Recognized while in the Track Play mode." (manual p. 55), and narrows the two song messages to a stopped instrument: "Recognized while in STOP of the Track Play mode." (manual p. 55). The instrument sends each when its number is set: Song Position "When the measure number is set." (manual p. 55) and Song Select "When the track # is set." (manual p. 55). One more state hears nothing: in the tape interface mode, "all MIDI messages are ignored." (manual p. 55).

FIFTEEN VOICES ON NINETEEN NOTE NUMBERS FROM THE FACTORY. "Originally, received note numbers are assigned as follows:" (manual p. 55) and fifteen rows, which the MIDI chapter draws as a keyboard headed "Drum Voices and corresponding Key Numbers. (MIDI IN)" (manual p. 44). Eleven voices have one number and four have two: Low Tom 41 and 43, Closed Hi-Hat 42 and 44, Mid Tom 45 and 47, High Tom 48 and 50. The chart gives the same nineteen as 35-51, 54, 56 (manual p. 50). voices lists both numbers of each pair, the lower first, which is the page's order and puts first the number the instrument itself sends for the voice in its normal setting, described below. Until 2026-10-13 it held the lower alone, and the higher was in these words.

AND THE OWNER CAN TEACH IT OTHER NUMBERS, WHICH IS WHY note_map IS learned. In the key number setting mode, "Select a drum voice and hold the corresponding Main Key down, and without releasing it, press a key on the connected instrument." (manual p. 45). "The key numbers available for this assignment are 35 to 98." (manual p. 45), and "Several key numbers can be set to one voice, but the same number cannot be assigned to more than one voice." (manual p. 45): a number given to a second voice is taken from the first, "the previous voice will be automatically dropped." (manual p. 45), and a number sent a second time to a held key is taken away again, "press the same key again." (manual p. 45). The step before is pressing Track Clear, of which the page says only "This clears previous key number assignment." (manual p. 45), not whether that is one voice's or every voice's. The implementation says the numbers are assigned "by panel operation, and then they will be memorized." (manual p. 55). The MIDI chapter also gives the way back to the initial setting (manual p. 44).

WHAT IT SENDS HAS TWO SETTINGS, AND IT SENDS IN PLACE OF SOUNDING. In Track Playing mode with the rhythm not running, Shift held with MIDI Channel and Instrument/Guide switches the instrument between sounding its own voices and sending key messages (manual p. 46): "When the Composer is transmitting MIDI message, the built-in voices do not output any sound." (manual p. 46). "The Key message transmitting mode is available only while in the Track Play mode. In this mode, only the programmed sounds will be transmitted." (manual p. 46). Each voice is sent on one number, from one of two sets that, in the same state, Shift held with MIDI Channel and Last Step alternates between (manual p. 46). The implementation calls them Setting A and Setting B (manual p. 55) and the MIDI chapter draws them as two keyboards (manual p. 46). Setting A, "Setting A: Normal." (manual p. 55), is the first number of each voice in voices below. Setting B is the numbers from 36 to 50 in another order: Bass Drum 1 on 36 and 2 on 37, Snare Drum 1 on 38 and 2 on 39, Low Tom 40, Mid Tom 41, High Tom 42, Rim Shot 43, Cowbell 44, Hand Clap 45, Tambourine 46, Closed Hi-Hat 47, Open Hi-Hat 48, Crash Cymbal 49 and Ride Cymbal 50. So a TR-707 sending Setting B does not play a factory TR-707 as itself: only Snare Drum 1 on 38 and Crash Cymbal on 49 arrive as themselves, and its second bass drum, on 37, arrives as the rim shot. Both settings are in voices_sent below. Until 2026-10-13 the format had no field for a map of what is sent, and Setting B was in these words alone.

VELOCITY BOTH WAYS, AND NO NOTE OFF HEARD. Received as vvvvvvv = 1 - 127 and sent as vvvvvvv = 40 - 124 (manual p. 55), which the chart gives as v=1-127 and 9n v=40-124 (manual p. 50). No page says what a received velocity does to the sound, nor what decides the velocity it sends. A note off is sent as a note on with a velocity of nought, and "All the note OFF messages are ignored." (manual p. 55).

BY THE CHART IT LISTENS ON EVERY CHANNEL UNTIL OMNI IS TURNED OFF. The chart's Mode row gives Mode 3 as the transmitted default and Mode 1 as the recognised one, lists OMNI ON OFF as the messages recognised, and remarks that MONO and POLY are ignored (manual p. 50); so mode is 1 received and 3 sent, as roland/juno_106 records its own. OMNI is also a panel setting, shown by a bar in the display (manual p. 43). One channel serves both directions, "one CH for both receive and send" (manual p. 53), from 1 to 16, set with the Main Keys (manual p. 42), and it is kept: "When the power is applied, the channel is set to the last channel." (manual p. 55).

CLOCK, START, CONTINUE AND STOP BOTH WAYS, AND HEARD ONLY IN MIDI SYNC MODE. The chart circles Clock and Commands in both columns and writes SYNC mode = MIDI beside the recognised ones (manual p. 50); the implementation marks all four received messages "When the SYNC mode is at MIDI." (manual p. 55). The sync mode is one of four, DIN, tape, MIDI and internal (manual pp. 38-39), and in MIDI sync "the tempo and start/stop are controlled by the master device." (manual p. 39). By the implementation's note the clock it sends follows whatever it is synchronised to, its own tempo, the received clock or the DIN clock (manual p. 55); the note has no row for tape sync. Song Position and Song Select are circled both ways as well, Song Select with (0-3) (manual p. 50), which is the four tracks counted from nought (manual p. 55); the format has no field for either. Active Sense and Reset are crossed as recognised and marked in the transmitted column with the note "If received when SYNC mode is MIDI." (manual p. 50), which reads as passing them on; the implementation's tables list neither.

SYSTEM EXCLUSIVE CARRIES WHAT THE IMPLEMENTATION CALLS SEQUENCE DATA. Circled both ways and remarked "For rhythm seq" (manual p. 50); both tables list it as Sequence Data, under Roland's identifier (manual p. 55), and neither says what the data holds. The implementation's last section sets out a handshake of eight message types for sending and requesting a file (manual pp. 55-56), in which, as the section sets it out, the instrument only answers: it sends its data when a file is requested and takes data when one is offered, in fifteen blocks, and neither the MIDI chapter nor the operation table gives a way to start a transfer from the panel. The page's own bytes do not agree. The recognised row prints its third byte as 0100 0010, where the transmitted row prints 0xxx xxxx and the handshake section gives the data message's operation code as 0101 0010 (manual p. 55); none of the eight operation codes is 0100 0010 (manual pp. 55-56).

FIVE PAIRS OF VOICES CANNOT SOUND TOGETHER, AND NO PAGE COUNTS WHAT CAN. "It is not possible to output the following pairs of voices at the same time." (manual p. 8): the two bass drums, the two snare drums, rim shot and cowbell, hand clap and tambourine, closed and open hi-hat. That would leave ten of the fifteen at once, which is the number of Multi Outputs the specifications list (manual p. 47). But page 8 says it of the voices as numbered by their keys, with a written step as its one example, and does not mention notes received; and no page states a count, so polyphony is not recorded.

THE MANUAL GIVES THREE PROCEDURES TWICE, AND DIFFERENTLY. The MIDI chapter sets OMNI in "the Track Writing mode with the rhythm not running" (manual p. 43), over a figure whose display reads TRACK PLAY, where the operation table says "Set the Composer to Track Playing mode." (manual p. 53). The chapter restores the key numbers in Track Playing mode (manual p. 44) and assigns them after "Enter the Track Writing mode, without the rhythm having run." (manual p. 45), where the table says Track Playing mode for both (manual p. 53). And the sync chapter changes the sync mode in Track Play mode (manual pp. 38-39) where the table says "Set the Composer to Track Writing mode." (manual p. 54). In each the manual names two modes and does not say whether both work. Until 2026-10-12 none was anything a field holds. The voices' part is now Track Playing mode's, on the sentences of the MIDI chapter and the implementation, and the two modes given for teaching a key number stay in words.

AND WHAT RESTORING THE KEY NUMBERS RESTORES IS TOLD TWO WAYS. By the MIDI chapter, pressing the Instrument/Guide button in the key number setting mode means "the initial setting is returned." (manual p. 44), under the keyboard of received numbers on that page. The operation table calls the same presses "Set the same Key number as MIDI out." (manual p. 53), over a small keyboard that has labels under the keys from 36 to 50, which are Setting B's, in print too small in the scan to read as words. The factory map carried here is the one three places agree on: the chapter's keyboard (manual p. 44), the implementation's list (manual p. 55) and the chart's range (manual p. 50).

NOT RECORDED:

AND ONE DOCUMENT THE MANUAL POINTS TO THAT ROLAND DOES NOT SERVE. The MIDI chapter opens by sending the reader to a separate volume called MIDI (manual p. 42), and the specifications list MIDI after Owner's Manual among the accessories (manual p. 47), as the JX-8P's and the αJUNO-2's manuals point to one. The archive lists no such volume, and nothing in the manual says whether it is about this instrument or about MIDI in general.