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Rhodes Chroma Polaris MIDI CC chart, NRPN and OSC map

The Rhodes Chroma Polaris MIDI implementation: 48 CC, each named, for Claude (MCP), SuperCollider or any OSC app.

Device Rhodes Chroma Polaris
Vendor Rhodes
OSC prefix /chroma_polaris
Source πŸŽ›οΈ Derived from an Electra One community preset
Revision per Electra preset
Upstream electra-preset
Driver file devices/rhodes/chroma_polaris.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 β€” 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/rhodes/chroma_polaris.json --out-port <N> --in-port <M>

Then send OSC to 127.0.0.1:7777, for example:

osc-bridge osc-send /chroma_polaris/tune 30

From Claude or any MCP client, the osc-bridge mcp server exposes this driver as chroma_polaris: ask β€œwhat can the Rhodes Chroma Polaris do?” and it reads this map with list_routes. See the MCP guide.

MIDI CC and NRPN parameters (48)

OSC address CC NRPN (MSB/LSB) Range Nature Section
/chroma_polaris/tune 22 0–60 continuous
/chroma_polaris/wave 30 0–127 continuous
/chroma_polaris/pw 96 -64–63 continuous
/chroma_polaris/pwm_source 98 0–127 continuous
/chroma_polaris/pwm 100 -64–63 continuous
/chroma_polaris/lfo 24 -64–63 continuous
/chroma_polaris/tune 23 0–60 continuous
/chroma_polaris/wave 31 0–127 continuous
/chroma_polaris/pw 97 -64–63 continuous
/chroma_polaris/pwm_source 99 0–127 continuous
/chroma_polaris/pwm 101 -64–63 continuous
/chroma_polaris/lfo 25 -64–63 continuous
/chroma_polaris/detune 27 -64–63 continuous
/chroma_polaris/env_osc2 26 -64–63 continuous
/chroma_polaris/sync 29 0–127 continuous
/chroma_polaris/ring_mod 28 0–127 continuous
/chroma_polaris/noise 102 0–127 continuous
/chroma_polaris/lfo_wave 6 0–127 continuous
/chroma_polaris/cutoff 103 0–127 continuous
/chroma_polaris/resonance 104 0–7 continuous
/chroma_polaris/env 106 -64–63 continuous
/chroma_polaris/lfo 105 -64–63 continuous
/chroma_polaris/keytrack 107 -64–63 continuous
/chroma_polaris/lfo_rate 4 0–127 continuous
/chroma_polaris/dynamic 12 0–127 continuous
/chroma_polaris/attack 13 0–63 continuous
/chroma_polaris/attack 14 0–63 continuous
/chroma_polaris/attack 15 0–63 continuous
/chroma_polaris/attack 17 0–63 continuous
/chroma_polaris/lfo_delay 7 0–63 continuous
/chroma_polaris/dynamic 18 0–127 continuous
/chroma_polaris/attack 19 0–63 continuous
/chroma_polaris/attack 20 0–63 continuous
/chroma_polaris/attack 21 0–63 continuous
/chroma_polaris/sustain_decay 16 0–63 continuous
/chroma_polaris/volume 2 0–127 continuous
/chroma_polaris/pb_range 10 -16–15 continuous
/chroma_polaris/mod_range 8 0–15 continuous
/chroma_polaris/glide 3 0–63 continuous
/chroma_polaris/pitch_aft 11 -16–15 continuous
/chroma_polaris/lfo_vco_aft 9 0–15 continuous
/chroma_polaris/lfo_rate_aft 5 -64–63 continuous
/chroma_polaris/cutoff_aft 108 -64–63 continuous
/chroma_polaris/volume_aft 109 0–63 continuous
/chroma_polaris/link_mode 112 0–127 continuous
/chroma_polaris/keyb_split 114 0–60 continuous
/chroma_polaris/slider_assign 111 0–13 continuous
/chroma_polaris/oct_minus 115 0–127 continuous

Performance MIDI

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

Frequently asked questions

Which MIDI CC controls the filter cutoff on the Rhodes Chroma Polaris?

CC 103 (0–127), named /chroma_polaris/cutoff in SynthHub's map.

How many parameters of the Rhodes Chroma Polaris can be controlled over MIDI?

SynthHub's map of the Rhodes Chroma Polaris lists 48 MIDI CC 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 Rhodes Chroma Polaris?

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