Please update the firmware to the latest version. This feature was added in later firmware versions and may not exist in the one currently on your Terra:
L+Y+H(parameter) enters Terra into MIDI Mode where you set one of 3 different MIDI modes for Terra. Please see the manual for the explanations on the three MIDI modes.
With the latest firmware, holding that combination and then pressing Echo puts Terra into Omnichord mode where pressed notes follow the tuning of the incoming MIDI notes:
V1.4
Release date 18.11.2023
Changes have not yet been put to the manual.
Added "OmniChord" mode.
While setting MIDI mode (L+Y(TUNE)+H(Parametric Hold)) press ECHO sensor for toggling "OmniChord" mode on\off.
When the mode is on it receives notes from the MIDI IN on the channel that is set as Terra MIDI channel number (see MIDI OUTPUT)
and assign it to TERRA sensors from 1 to how many keys you pressed simultaneously.
This way, you can turn TERRA to a harp that changes its tuning according to the harmony of your composition.
You can connect a MIDI sequencer that sends to TERRA notes of the current chord, using up to all 12 TERRA's sensors
with octaves, 7th and all richness and just make a stroke across the notes sensors and TERRA will play in the perfect tune
with your composition.
After powering on TERRA, the "OmniChord" mode is in off state (default).