A MIDI-in, MIDI-out note transposer. Play in a comfortable key and sound in the band's key, or drop a keyboard part an octave for a bass line. It has one main knob, an octave knob and an on/off switch, so it also works as the brain of a simple one-knob MIDI pedal.
Controls
- Transpose shifts notes from 24 semitones down to 24 up, in whole semitones. The centre is unchanged.
- Octave adds up to two whole octaves up or down on top of that.
- Transpose on switches the shift in and out, the way a footswitch would.
The panel shows what middle C (C4) becomes with the current settings, so you can read the result at a glance.
How it behaves
- Held notes are safe. Turning the knob, changing octave or switching off while you hold keys never leaves a note hanging downstream: each release always ends the pitch its note started as.
- Notes pushed out of range are dropped. A note that would land below the lowest or above the highest MIDI note is not sent, and neither is its release.
- Channels are kept. A note arriving on channel 4 leaves on channel 4.
- Notes only. Control changes, pitch bend and program changes are not passed through.
Getting started
Connect a MIDI source, such as a keyboard or a sequencer, to its input and an instrument to its output. The presets cover common jobs: Unity, Capo 2 (play in C, sound in D), Up a fourth, Down half step (to match a band tuned down to E♭), Octave up and Bass octave.
