MIDI and MPE
It might not make sound, but it talks a lot.
Chords sends everything it plays on the MIDIpad Chords port, open from the moment the app runs.
What it's doing under the hood
- Energy - how hard each string is playing right now - goes out as pressure. A string swells as you feed it and dies as it fades, and a synth patched to pressure breathes along with it.
- Agitation - how bright each string's voice is - goes out as CC74, which is the brightness most MPE synths are already listening for. It rests at 64 and rises from there. Where you strike and where your finger rests colours it.
Both are sent just before each note, so a pluck arrives with its loudness and colour already on it.
MIDI outputs
Chords channels, in Settings → MIDI, picks which type of MIDI output MIDIpad Chords sends.
| Mode | Channels | Energy | Agitation |
|---|---|---|---|
| MPE | Master on 1, one string per channel on 2-7 | Channel pressure, per string | CC74, per string |
| Multi-channel | One channel per string | Channel pressure, per channel | CC74, per channel |
| Poly aftertouch | Everything on channel 1 | Poly key pressure, per note | One CC74 |
| Single channel | Everything on channel 1 | One channel pressure | One CC74 |
MPE
MPE sends each string on its own channel alongside a master channel. The zone announcement and the message-by-message account are in the MIDI reference.
Multi-channel
Multi-channel is MPE without the master channel: the same one-string-per-channel stream, shifted down so the six strings sit on channels 1 to 6, and nothing announced. It's for the one-synth-per-string setup - six tracks, each filtered to one channel, a different instrument on each - and for gear that reads channels but doesn't know what MPE is. Leave the port's MPE switch off in your DAW for this one; with it on, channel 1 gets read as a master channel and the low string goes missing.
Six String channels rows appear under the setting when Multi-channel is picked, one per string from the low string up, and each can go out on any channel from 1 to 16. Put strings on the same channel and they arrive there as one instrument, the way Single channel works: one pressure that follows the loudest of them, one CC74 that follows the brightest, no pitch bend. So the low three strings on channel 1 and the high three on channel 2 gives you a bass track and a chord track from one chord, and a DAW arpeggiator or an octave doubler on either track hears exactly the strings you sent it.
Poly aftertouch
Poly aftertouch keeps the per-string energy, as polyphonic key pressure keyed to each note. A synth that reads poly aftertouch hears every string breathe on its own without needing MPE anywhere. Agitation becomes one CC74 for the whole instrument, the brightest string.
Single channel
Single channel is what a plain MIDI keyboard sends: one channel pressure that follows the loudest string, one CC74 that follows the brightest. Pick it when in doubt, and Poly aftertouch when the synth supports it.