Written from devices/roland/mc-303.vendor.fw-unknown.jsonEdit on GitHub JSON

Roland MC-303 MIDI CC chart, NRPN and OSC map

The Roland MC-303 MIDI implementation: 21 CC, 13 NRPN, 3 RPN, 192 SysEx commands, each named, for Claude (MCP), SuperCollider or any OSC app.

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real unitnot yet checked

Not checked on a real Roland MC-303 yet. Own one? Load a sound or send a control, and tell us whether it worked.

Maker: Roland
Version: MIDI Implementation Version 1.00 (Mar. 25, 1996); OS version not stated
Source: maker's documentation
OSC prefix: /mc_303

Use it

Find the MIDI ports, then start the bridge with this driver:

osc-bridge detect        # prints the ready-to-run line for what is plugged in
osc-bridge run --device devices/roland/mc-303.vendor.fw-unknown.json --out-port <N> --in-port <M>

Then send OSC to 127.0.0.1:7777, for example:

osc-bridge osc-send /mc_303/bank/select_msb 63

From Claude or any MCP client, the osc-bridge mcp server exposes this driver as mc_303: ask “what can the Roland MC-303 do?” and it reads this map with list_routes. See the MCP guide.

MIDI controls

229 controls, each with its number, its range and the name to send

Program

Control	CC	Range	Name to send
Bank select msb	0	discrete	`/mc_303/bank/select_msb`
Bank select lsb	32	discrete	`/mc_303/bank/select_lsb`

Controllers

Control	CC	Range	Name to send
Modulation	1	0–127	`/mc_303/modulation`
Portamento time	5	0–127	`/mc_303/portamento_time`
Hold	64	switch	`/mc_303/hold`
Portamento	65	switch	`/mc_303/portamento`
Sostenuto	66	switch	`/mc_303/sostenuto`
Soft	67	switch	`/mc_303/soft`
Portamento control	84	discrete	`/mc_303/portamento_control`

Mixer

Control	CC	Range	Name to send
Volume	7	0–127	`/mc_303/volume`
Pan	10	0–127	`/mc_303/pan`
Expression	11	0–127	`/mc_303/expression`

Effects

Control	CC	Range	Name to send
Reverb send	91	0–127	`/mc_303/reverb_send`
Chorus send	93	0–127	`/mc_303/chorus_send`

Channel mode

Control	CC	Range	Name to send
All sounds off	120	trigger	`/mc_303/all_sounds_off`
Reset all controllers	121	trigger	`/mc_303/reset_all_controllers`
All notes off	123	trigger	`/mc_303/all_notes_off`
Omni off	124	trigger	`/mc_303/omni_off`
Omni on	125	trigger	`/mc_303/omni_on`
Poly	127	trigger	`/mc_303/poly`
Mono	126	discrete	`/mc_303/mono`

Registered parameters

Control	RPN (MSB/LSB)	Range	Name to send
Rpn pitch bend sensitivity	RPN 0 / 0	discrete	`/mc_303/rpn/pitch_bend_sensitivity`
Rpn master fine tuning	RPN 0 / 1	0–16383	`/mc_303/rpn/master_fine_tuning`
Rpn master coarse tuning	RPN 0 / 2	discrete	`/mc_303/rpn/master_coarse_tuning`

NRPN

Control	NRPN (MSB/LSB)	Range	Name to send
Vibrato rate	1 / 8	14–114	`/mc_303/nrpn/vibrato_rate`
Vibrato depth	1 / 9	14–114	`/mc_303/nrpn/vibrato_depth`
Vibrato delay	1 / 10	14–114	`/mc_303/nrpn/vibrato_delay`
Tvf cutoff	1 / 32	14–114	`/mc_303/nrpn/tvf_cutoff`
Tvf resonance	1 / 33	14–114	`/mc_303/nrpn/tvf_resonance`
Env attack	1 / 99	14–114	`/mc_303/nrpn/env_attack`
Env decay	1 / 100	14–114	`/mc_303/nrpn/env_decay`
Env release	1 / 102	14–114	`/mc_303/nrpn/env_release`

NRPN (drum)

Control	NRPN (MSB/LSB)	Range	Name to send
Nrpn drum pitch coarse	24 / 0–127	0–127	`/mc_303/nrpn/drum/pitch_coarse`
Nrpn drum level	26 / 0–127	0–127	`/mc_303/nrpn/drum/level`
Nrpn drum pan	28 / 0–127	0–127	`/mc_303/nrpn/drum/pan`
Nrpn drum reverb send	29 / 0–127	0–127	`/mc_303/nrpn/drum/reverb_send`
Nrpn drum chorus send	30 / 0–127	0–127	`/mc_303/nrpn/drum/chorus_send`

SysEx commands

Command	Arguments	Name to send
Transport clock		`/mc_303/transport/clock`
Transport start		`/mc_303/transport/start`
Transport continue		`/mc_303/transport/continue`
Transport stop		`/mc_303/transport/stop`
Identity request		`/mc_303/identity/request`
Master volume	value: u7	`/mc_303/master/volume`
System master volume	value: u7	`/mc_303/system/master_volume`
System master key shift	value: u7	`/mc_303/system/master_key_shift`
System master pan	value: u7	`/mc_303/system/master_pan`
System mode set	mode: enum	`/mc_303/system/mode_set`
System reverb macro	type: enum	`/mc_303/system/reverb/macro`
System reverb character	value: u7	`/mc_303/system/reverb/character`
System reverb pre lpf	value: u7	`/mc_303/system/reverb/pre_lpf`
System reverb level	value: u7	`/mc_303/system/reverb/level`
System reverb time	value: u7	`/mc_303/system/reverb/time`
System reverb delay feedback	value: u7	`/mc_303/system/reverb/delay_feedback`
System reverb send to chorus	value: u7	`/mc_303/system/reverb/send_to_chorus`
System chorus macro	type: enum	`/mc_303/system/chorus/macro`
System chorus pre lpf	value: u7	`/mc_303/system/chorus/pre_lpf`
System chorus level	value: u7	`/mc_303/system/chorus/level`
System chorus feedback	value: u7	`/mc_303/system/chorus/feedback`
System chorus delay	value: u7	`/mc_303/system/chorus/delay`
System chorus rate	value: u7	`/mc_303/system/chorus/rate`
System chorus depth	value: u7	`/mc_303/system/chorus/depth`
System chorus send to reverb	value: u7	`/mc_303/system/chorus/send_to_reverb`
Part {block} tone number	block: u7, bank: u7, program: u7	`/mc_303/part/{block}/tone_number`
Part {block} rx channel	block: u7, value: u7	`/mc_303/part/{block}/rx/channel`
Part {block} rx pitch bend	block: u7, value: enum	`/mc_303/part/{block}/rx/pitch_bend`
Part {block} rx ch pressure	block: u7, value: enum	`/mc_303/part/{block}/rx/ch_pressure`
Part {block} rx program change	block: u7, value: enum	`/mc_303/part/{block}/rx/program_change`
Part {block} rx control change	block: u7, value: enum	`/mc_303/part/{block}/rx/control_change`
Part {block} rx poly pressure	block: u7, value: enum	`/mc_303/part/{block}/rx/poly_pressure`
Part {block} rx note message	block: u7, value: enum	`/mc_303/part/{block}/rx/note_message`
Part {block} rx rpn	block: u7, value: enum	`/mc_303/part/{block}/rx/rpn`
Part {block} rx nrpn	block: u7, value: enum	`/mc_303/part/{block}/rx/nrpn`
Part {block} rx modulation	block: u7, value: enum	`/mc_303/part/{block}/rx/modulation`
Part {block} rx volume	block: u7, value: enum	`/mc_303/part/{block}/rx/volume`
Part {block} rx panpot	block: u7, value: enum	`/mc_303/part/{block}/rx/panpot`
Part {block} rx expression	block: u7, value: enum	`/mc_303/part/{block}/rx/expression`
Part {block} rx hold1	block: u7, value: enum	`/mc_303/part/{block}/rx/hold1`
Part {block} rx portamento	block: u7, value: enum	`/mc_303/part/{block}/rx/portamento`
Part {block} rx sostenuto	block: u7, value: enum	`/mc_303/part/{block}/rx/sostenuto`
Part {block} rx soft	block: u7, value: enum	`/mc_303/part/{block}/rx/soft`
Part {block} rx bank select	block: u7, value: enum	`/mc_303/part/{block}/rx/bank_select`
Part {block} mono poly	block: u7, value: enum	`/mc_303/part/{block}/mono_poly`
Part {block} assign mode	block: u7, value: enum	`/mc_303/part/{block}/assign_mode`
Part {block} use for rhythm part	block: u7, value: enum	`/mc_303/part/{block}/use_for_rhythm_part`
Part {block} pitch key shift	block: u7, value: u7	`/mc_303/part/{block}/pitch_key_shift`
Part {block} level	block: u7, value: u7	`/mc_303/part/{block}/level`
Part {block} velocity sense depth	block: u7, value: u7	`/mc_303/part/{block}/velocity_sense_depth`
Part {block} velocity sense offset	block: u7, value: u7	`/mc_303/part/{block}/velocity_sense_offset`
Part {block} pan	block: u7, value: u7	`/mc_303/part/{block}/pan`
Part {block} key range low	block: u7, value: u7	`/mc_303/part/{block}/key_range_low`
Part {block} key range high	block: u7, value: u7	`/mc_303/part/{block}/key_range_high`
Part {block} chorus send	block: u7, value: u7	`/mc_303/part/{block}/chorus_send`
Part {block} reverb send	block: u7, value: u7	`/mc_303/part/{block}/reverb_send`
Part {block} cc1 controller number	block: u7, value: u7	`/mc_303/part/{block}/cc1_controller_number`
Part {block} cc2 controller number	block: u7, value: u7	`/mc_303/part/{block}/cc2_controller_number`
Part {block} tone modify1	block: u7, value: u7	`/mc_303/part/{block}/tone_modify1`
Part {block} tone modify2	block: u7, value: u7	`/mc_303/part/{block}/tone_modify2`
Part {block} tone modify3	block: u7, value: u7	`/mc_303/part/{block}/tone_modify3`
Part {block} tone modify4	block: u7, value: u7	`/mc_303/part/{block}/tone_modify4`
Part {block} tone modify5	block: u7, value: u7	`/mc_303/part/{block}/tone_modify5`
Part {block} tone modify6	block: u7, value: u7	`/mc_303/part/{block}/tone_modify6`
Part {block} tone modify7	block: u7, value: u7	`/mc_303/part/{block}/tone_modify7`
Part {block} tone modify8	block: u7, value: u7	`/mc_303/part/{block}/tone_modify8`
Part {block} lfo waveform	block: u7, value: enum	`/mc_303/part/{block}/lfo_waveform`
Part {block} scale tuning c	block: u7, value: u7	`/mc_303/part/{block}/scale_tuning/c`
Part {block} scale tuning cs	block: u7, value: u7	`/mc_303/part/{block}/scale_tuning/cs`
Part {block} scale tuning d	block: u7, value: u7	`/mc_303/part/{block}/scale_tuning/d`
Part {block} scale tuning ds	block: u7, value: u7	`/mc_303/part/{block}/scale_tuning/ds`
Part {block} scale tuning e	block: u7, value: u7	`/mc_303/part/{block}/scale_tuning/e`
Part {block} scale tuning f	block: u7, value: u7	`/mc_303/part/{block}/scale_tuning/f`
Part {block} scale tuning fs	block: u7, value: u7	`/mc_303/part/{block}/scale_tuning/fs`
Part {block} scale tuning g	block: u7, value: u7	`/mc_303/part/{block}/scale_tuning/g`
Part {block} scale tuning gs	block: u7, value: u7	`/mc_303/part/{block}/scale_tuning/gs`
Part {block} scale tuning a	block: u7, value: u7	`/mc_303/part/{block}/scale_tuning/a`
Part {block} scale tuning as	block: u7, value: u7	`/mc_303/part/{block}/scale_tuning/as`
Part {block} scale tuning b	block: u7, value: u7	`/mc_303/part/{block}/scale_tuning/b`
Part {block} mod pitch control	block: u7, value: u7	`/mc_303/part/{block}/mod/pitch_control`
Part {block} mod tvf cutoff control	block: u7, value: u7	`/mc_303/part/{block}/mod/tvf_cutoff_control`
Part {block} mod amplitude control	block: u7, value: u7	`/mc_303/part/{block}/mod/amplitude_control`
Part {block} mod lfo1 rate control	block: u7, value: u7	`/mc_303/part/{block}/mod/lfo1_rate_control`
Part {block} mod lfo1 pitch depth	block: u7, value: u7	`/mc_303/part/{block}/mod/lfo1_pitch_depth`
Part {block} mod lfo1 tvf depth	block: u7, value: u7	`/mc_303/part/{block}/mod/lfo1_tvf_depth`
Part {block} mod lfo1 tva depth	block: u7, value: u7	`/mc_303/part/{block}/mod/lfo1_tva_depth`
Part {block} mod lfo2 rate control	block: u7, value: u7	`/mc_303/part/{block}/mod/lfo2_rate_control`
Part {block} mod lfo2 pitch depth	block: u7, value: u7	`/mc_303/part/{block}/mod/lfo2_pitch_depth`
Part {block} mod lfo2 tvf depth	block: u7, value: u7	`/mc_303/part/{block}/mod/lfo2_tvf_depth`
Part {block} mod lfo2 tva depth	block: u7, value: u7	`/mc_303/part/{block}/mod/lfo2_tva_depth`
Part {block} bend pitch control	block: u7, value: u7	`/mc_303/part/{block}/bend/pitch_control`
Part {block} bend tvf cutoff control	block: u7, value: u7	`/mc_303/part/{block}/bend/tvf_cutoff_control`
Part {block} bend amplitude control	block: u7, value: u7	`/mc_303/part/{block}/bend/amplitude_control`
Part {block} bend lfo1 rate control	block: u7, value: u7	`/mc_303/part/{block}/bend/lfo1_rate_control`
Part {block} bend lfo1 pitch depth	block: u7, value: u7	`/mc_303/part/{block}/bend/lfo1_pitch_depth`
Part {block} bend lfo1 tvf depth	block: u7, value: u7	`/mc_303/part/{block}/bend/lfo1_tvf_depth`
Part {block} bend lfo1 tva depth	block: u7, value: u7	`/mc_303/part/{block}/bend/lfo1_tva_depth`
Part {block} bend lfo2 rate control	block: u7, value: u7	`/mc_303/part/{block}/bend/lfo2_rate_control`
Part {block} bend lfo2 pitch depth	block: u7, value: u7	`/mc_303/part/{block}/bend/lfo2_pitch_depth`
Part {block} bend lfo2 tvf depth	block: u7, value: u7	`/mc_303/part/{block}/bend/lfo2_tvf_depth`
Part {block} bend lfo2 tva depth	block: u7, value: u7	`/mc_303/part/{block}/bend/lfo2_tva_depth`
Part {block} caf pitch control	block: u7, value: u7	`/mc_303/part/{block}/caf/pitch_control`
Part {block} caf tvf cutoff control	block: u7, value: u7	`/mc_303/part/{block}/caf/tvf_cutoff_control`
Part {block} caf amplitude control	block: u7, value: u7	`/mc_303/part/{block}/caf/amplitude_control`
Part {block} caf lfo1 rate control	block: u7, value: u7	`/mc_303/part/{block}/caf/lfo1_rate_control`
Part {block} caf lfo1 pitch depth	block: u7, value: u7	`/mc_303/part/{block}/caf/lfo1_pitch_depth`
Part {block} caf lfo1 tvf depth	block: u7, value: u7	`/mc_303/part/{block}/caf/lfo1_tvf_depth`
Part {block} caf lfo1 tva depth	block: u7, value: u7	`/mc_303/part/{block}/caf/lfo1_tva_depth`
Part {block} caf lfo2 rate control	block: u7, value: u7	`/mc_303/part/{block}/caf/lfo2_rate_control`
Part {block} caf lfo2 pitch depth	block: u7, value: u7	`/mc_303/part/{block}/caf/lfo2_pitch_depth`
Part {block} caf lfo2 tvf depth	block: u7, value: u7	`/mc_303/part/{block}/caf/lfo2_tvf_depth`
Part {block} caf lfo2 tva depth	block: u7, value: u7	`/mc_303/part/{block}/caf/lfo2_tva_depth`
Part {block} paf pitch control	block: u7, value: u7	`/mc_303/part/{block}/paf/pitch_control`
Part {block} paf tvf cutoff control	block: u7, value: u7	`/mc_303/part/{block}/paf/tvf_cutoff_control`
Part {block} paf amplitude control	block: u7, value: u7	`/mc_303/part/{block}/paf/amplitude_control`
Part {block} paf lfo1 rate control	block: u7, value: u7	`/mc_303/part/{block}/paf/lfo1_rate_control`
Part {block} paf lfo1 pitch depth	block: u7, value: u7	`/mc_303/part/{block}/paf/lfo1_pitch_depth`
Part {block} paf lfo1 tvf depth	block: u7, value: u7	`/mc_303/part/{block}/paf/lfo1_tvf_depth`
Part {block} paf lfo1 tva depth	block: u7, value: u7	`/mc_303/part/{block}/paf/lfo1_tva_depth`
Part {block} paf lfo2 rate control	block: u7, value: u7	`/mc_303/part/{block}/paf/lfo2_rate_control`
Part {block} paf lfo2 pitch depth	block: u7, value: u7	`/mc_303/part/{block}/paf/lfo2_pitch_depth`
Part {block} paf lfo2 tvf depth	block: u7, value: u7	`/mc_303/part/{block}/paf/lfo2_tvf_depth`
Part {block} paf lfo2 tva depth	block: u7, value: u7	`/mc_303/part/{block}/paf/lfo2_tva_depth`
Part {block} cc1 pitch control	block: u7, value: u7	`/mc_303/part/{block}/cc1/pitch_control`
Part {block} cc1 tvf cutoff control	block: u7, value: u7	`/mc_303/part/{block}/cc1/tvf_cutoff_control`
Part {block} cc1 amplitude control	block: u7, value: u7	`/mc_303/part/{block}/cc1/amplitude_control`
Part {block} cc1 lfo1 rate control	block: u7, value: u7	`/mc_303/part/{block}/cc1/lfo1_rate_control`
Part {block} cc1 lfo1 pitch depth	block: u7, value: u7	`/mc_303/part/{block}/cc1/lfo1_pitch_depth`
Part {block} cc1 lfo1 tvf depth	block: u7, value: u7	`/mc_303/part/{block}/cc1/lfo1_tvf_depth`
Part {block} cc1 lfo1 tva depth	block: u7, value: u7	`/mc_303/part/{block}/cc1/lfo1_tva_depth`
Part {block} cc1 lfo2 rate control	block: u7, value: u7	`/mc_303/part/{block}/cc1/lfo2_rate_control`
Part {block} cc1 lfo2 pitch depth	block: u7, value: u7	`/mc_303/part/{block}/cc1/lfo2_pitch_depth`
Part {block} cc1 lfo2 tvf depth	block: u7, value: u7	`/mc_303/part/{block}/cc1/lfo2_tvf_depth`
Part {block} cc1 lfo2 tva depth	block: u7, value: u7	`/mc_303/part/{block}/cc1/lfo2_tva_depth`
Part {block} cc2 pitch control	block: u7, value: u7	`/mc_303/part/{block}/cc2/pitch_control`
Part {block} cc2 tvf cutoff control	block: u7, value: u7	`/mc_303/part/{block}/cc2/tvf_cutoff_control`
Part {block} cc2 amplitude control	block: u7, value: u7	`/mc_303/part/{block}/cc2/amplitude_control`
Part {block} cc2 lfo1 rate control	block: u7, value: u7	`/mc_303/part/{block}/cc2/lfo1_rate_control`
Part {block} cc2 lfo1 pitch depth	block: u7, value: u7	`/mc_303/part/{block}/cc2/lfo1_pitch_depth`
Part {block} cc2 lfo1 tvf depth	block: u7, value: u7	`/mc_303/part/{block}/cc2/lfo1_tvf_depth`
Part {block} cc2 lfo1 tva depth	block: u7, value: u7	`/mc_303/part/{block}/cc2/lfo1_tva_depth`
Part {block} cc2 lfo2 rate control	block: u7, value: u7	`/mc_303/part/{block}/cc2/lfo2_rate_control`
Part {block} cc2 lfo2 pitch depth	block: u7, value: u7	`/mc_303/part/{block}/cc2/lfo2_pitch_depth`
Part {block} cc2 lfo2 tvf depth	block: u7, value: u7	`/mc_303/part/{block}/cc2/lfo2_tvf_depth`
Part {block} cc2 lfo2 tva depth	block: u7, value: u7	`/mc_303/part/{block}/cc2/lfo2_tva_depth`
Drum {map} {note} play note number	map: u7, note: u7, value: u7	`/mc_303/drum/{map}/{note}/play_note_number`
Drum {map} {note} level	map: u7, note: u7, value: u7	`/mc_303/drum/{map}/{note}/level`
Drum {map} {note} assign group	map: u7, note: u7, value: u7	`/mc_303/drum/{map}/{note}/assign_group`
Drum {map} {note} pan	map: u7, note: u7, value: u7	`/mc_303/drum/{map}/{note}/pan`
Drum {map} {note} reverb send	map: u7, note: u7, value: u7	`/mc_303/drum/{map}/{note}/reverb_send`
Drum {map} {note} chorus send	map: u7, note: u7, value: u7	`/mc_303/drum/{map}/{note}/chorus_send`
Drum {map} {note} rx note off	map: u7, note: u7, value: enum	`/mc_303/drum/{map}/{note}/rx_note_off`
Drum {map} {note} rx note on	map: u7, note: u7, value: enum	`/mc_303/drum/{map}/{note}/rx_note_on`
Request all		`/mc_303/request/all`
Request system1		`/mc_303/request/system1`
Request system2		`/mc_303/request/system2`
Request part block 0		`/mc_303/request/part_block_0`
Request part block 1		`/mc_303/request/part_block_1`
Request part block 2		`/mc_303/request/part_block_2`
Request part block 3		`/mc_303/request/part_block_3`
Request part block 4		`/mc_303/request/part_block_4`
Request part block 5		`/mc_303/request/part_block_5`
Request part block 6		`/mc_303/request/part_block_6`
Request part block 7		`/mc_303/request/part_block_7`
Request part block 8		`/mc_303/request/part_block_8`
Request part block 9		`/mc_303/request/part_block_9`
Request part block A		`/mc_303/request/part_block_A`
Request part block B		`/mc_303/request/part_block_B`
Request part block C		`/mc_303/request/part_block_C`
Request part block D		`/mc_303/request/part_block_D`
Request part block E		`/mc_303/request/part_block_E`
Request part block F		`/mc_303/request/part_block_F`
Request drum map1 play note number		`/mc_303/request/drum_map1/play_note_number`
Request drum map2 play note number		`/mc_303/request/drum_map2/play_note_number`
Request drum map1 level		`/mc_303/request/drum_map1/level`
Request drum map2 level		`/mc_303/request/drum_map2/level`
Request drum map1 assign group number		`/mc_303/request/drum_map1/assign_group_number`
Request drum map2 assign group number		`/mc_303/request/drum_map2/assign_group_number`
Request drum map1 panpot		`/mc_303/request/drum_map1/panpot`
Request drum map2 panpot		`/mc_303/request/drum_map2/panpot`
Request drum map1 reverb send level		`/mc_303/request/drum_map1/reverb_send_level`
Request drum map2 reverb send level		`/mc_303/request/drum_map2/reverb_send_level`
Request drum map1 chorus send level		`/mc_303/request/drum_map1/chorus_send_level`
Request drum map2 chorus send level		`/mc_303/request/drum_map2/chorus_send_level`
Request drum map1 rx note on off		`/mc_303/request/drum_map1/rx_note_on_off`
Request drum map2 rx note on off		`/mc_303/request/drum_map2/rx_note_on_off`
Request drum map1 name		`/mc_303/request/drum_map1/name`
Request drum map2 name		`/mc_303/request/drum_map2/name`
Request variation setup		`/mc_303/request/variation_setup`
Request song setup		`/mc_303/request/song_setup`
Request pattern setup		`/mc_303/request/pattern_setup`
Request song		`/mc_303/request/song`

Performance MIDI

Notes, pitch bend and any CC are also available: /mc_303/note/on <note> <velocity>, /mc_303/cc/<number> <value>, /mc_303/pitchbend <0-16383>, /mc_303/program_change <n>.

JSON

Limitations

Source: the scanned MC-303 Owner's Manual (MIDI implementation 1.00, 1996), read from the page images. Left out: MASTER TUNE (00 40 00 00) and PITCH OFFSET FINE (00 40 1x 17), sent as nibblized multi-byte data the bridge's frame engine cannot split; VOICE RESERVE (00 40 01 10, one 16-byte block whose other addresses cannot be starting addresses); the RPS Set, Pattern Set and User Pattern dump requests (11, 12 and 40 00 00 00), whose sizes are not legible in the scan. Bulk data is requested only, not decoded. Part parameters are addressed by block number, not MIDI channel (see each route). Notes play the part on that channel; the rhythm part's instruments depend on the drum map and are not listed as triggers. Normal Mode only transmits notes when Out Assign is Ext. Untested on hardware.

Frequently asked questions

How many parameters of the Roland MC-303 can be controlled over MIDI?

SynthHub's map of the Roland MC-303 lists 21 MIDI CC, 13 NRPN and 3 RPN parameters, each with its number, range and a readable name; the full chart is on this page.

Can an AI agent like Claude control the Roland MC-303?

Yes: SynthHub's hosted MCP server knows the Roland MC-303's MIDI map, and its browser relay lets the agent send it parameter changes or load a sound, each sound change confirmed by you.