Generalmusic GEM - RPX: MIDI CC, NRPN and OSC map¶
The Generalmusic GEM - RPX as named OSC addresses — 15 CC, 16 SysEx commands — ready to use from Claude (MCP), SuperCollider, Sonic Pi, TouchDesigner or any OSC app via osc-bridge.
| Device | Generalmusic GEM - RPX |
|---|---|
| Vendor | Generalmusic |
| OSC prefix | /gem_rpx |
| Source | 🎛️ Derived from an Electra One community preset |
| Revision | per Electra preset |
| Upstream | electra-preset |
| Driver file | devices/generalmusic/gem_rpx.json |
Not tested on the device yet
This driver comes from documentation or community data and has not been checked on real hardware. If you own one, a quick test and a pull request promoting it helps everyone — see CONTRIBUTING.
How do you control 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/generalmusic/gem_rpx.json --out-port <N> --in-port <M>
Then send OSC to 127.0.0.1:7777, for example:
From Claude or any MCP client, the osc-bridge mcp server exposes this driver as gem_rpx: ask “what can the Generalmusic GEM - RPX do?” and it reads this map with list_routes. See the MCP guide.
MIDI CC and NRPN parameters (15)¶
| OSC address | CC | NRPN (MSB/LSB) | Range | Nature | Section |
|---|---|---|---|---|---|
/gem_rpx/env |
73 | 0–127 | continuous | ||
/gem_rpx/env |
75 | 0–127 | continuous | ||
/gem_rpx/env |
72 | 0–127 | continuous | ||
/gem_rpx/all_sounds_off |
120 | 0–127 | continuous | ||
/gem_rpx/reset_all_cont |
121 | 0–127 | continuous | ||
/gem_rpx/reverb |
91 | 0–127 | continuous | ||
/gem_rpx/chorus |
93 | 0–127 | continuous | ||
/gem_rpx/cuttof |
74 | 0–127 | continuous | ||
/gem_rpx/resonance |
71 | 0–127 | continuous | ||
/gem_rpx/toggle |
65 | 0–127 | continuous | ||
/gem_rpx/port_control |
68 | 0–127 | continuous | ||
/gem_rpx/soft |
67 | 0–127 | continuous | ||
/gem_rpx/sostenuto |
66 | 0–127 | continuous | ||
/gem_rpx/sustain |
64 | 0–127 | continuous | ||
/gem_rpx/pan |
10 | -64–63 | continuous |
SysEx commands (16)¶
| OSC address | Arguments |
|---|---|
/gem_rpx/common_midi_ch |
val: u7 |
/gem_rpx/master_volume |
val: u7 |
/gem_rpx/mstr_transpose |
val: u7 |
/gem_rpx/mstr_fine_tune |
val: u7 |
/gem_rpx/fixed_velocity |
val: u7 |
/gem_rpx/velo_offset |
val: u7 |
/gem_rpx/custom_scale |
val: u7 |
/gem_rpx/perf_volume |
val: u7 |
/gem_rpx/type |
val: u7 |
/gem_rpx/volume |
val: u7 |
/gem_rpx/pre_delay |
val: u7 |
/gem_rpx/time |
val: u7 |
/gem_rpx/decay |
val: u7 |
/gem_rpx/efx_type |
val: u7 |
/gem_rpx/param_1 |
val: u7 |
/gem_rpx/param_2 |
val: u7 |
Performance MIDI¶
Notes, pitch bend and any CC are also available: /gem_rpx/note/on <note> <velocity>, /gem_rpx/cc/<number> <value>, /gem_rpx/pitchbend <0-16383>, /gem_rpx/program_change <n>.
Limitations¶
Imported from an Electra One community preset. The mapping reflects the preset author's editorial choices: parameter naming, ranges, and which params are exposed. Untested on hardware in this repo.