Driving Ableton's Spectral Resonator with a MIDI chord progression only works if you catch one setup detail: Mono mode plays a single note at a time, no matter how many notes you send it. Switching to Poly mode unlocks full chords, and the voice count control (2 up to 16) determines how many notes can ring simultaneously.
Once the chords are playing, Decay and HF Damp shape how long and how brightly the sound sustains, letting longer tails fade with duller or richer top end. Shift brightens the harmonic content, while Stretch spaces out the harmonics for a more hollow, detuned character.
The three modulation modes each give a distinct texture: Chorus adds width and phasing, Wander does something similar but more neutral, and Granular produces a glitchy, wind-chime-like digital sound. Mod-Rate and pitch modulation amount add further movement inside whichever mode is active.
Unison stacks slightly detuned copies of the underlying sine waves, with Unison Amount controlling the spread between them. Pushed up toward 8, the detuning gets dense enough that the processed chords start to blend back toward the character of the original drum loop they were built from.