TR-8 Velocity Arp

Purpose

Same model as the synth velocity arp, targeting the TR-8’s per-voice velocity arp arrays. Alt-kit aware: writes go to the main (tr8_velo_arp_*) or alt (tr8_velo_arp_*_alt) arrays depending on the TR-8 alt latch state.

Interaction

Two-stage editor. LHS LP: overview of all 8 rows’ arp patterns and the row/length selector. RHS LP: value editor for the selected row (column = arp step 1–8, row = value 0–7). Each RHS column shows one lit pad at the stored value’s height, not a filled bar. If a drum-cycle event arrives while this view is open, the view stays visible (so the editor can follow the new alt state) even though the sequencer selection snaps.

Shortcuts

LHS: overview side

Gesture	Where	Action	Modifiers
Press row R, col N	LP LHS	Select row R; a double-tap within 350 ms sets its length to N slots	none
SHIFT + press row R, col N	LP LHS	Select row R and set its length to N slots immediately	shift
Press row R, col 9	LP LHS col 9	Select row R without changing its length	none
SHIFT + MUTE + press row R, col 9	LP LHS col 9	Reset the pressed row’s voice to its canonical value: ghost rows 2, boom-tsk 7, all others 5 (alt-view-aware)	shift+mute
SHIFT + SOLO + press col 9	LP LHS col 9	Randomise the selected arp freely across values 0–7	shift+solo

RHS: value editor

Gesture	Where	Action	Modifiers
Press	LP RHS	Write the pressed row’s value into the selected row’s arp step (column 1–8)	none
SHIFT + MUTE + press row R	LP RHS	Reset: fill selected arp with row R’s value (alt-view-aware)	shift+mute
SHIFT + SOLO + press row R	LP RHS	Randomise: selected arp gaussian around row R	shift+solo

A stored length of 0 means one active slot, not disabled playback. Column 1 therefore parks the voice on its first velocity value. There is no off state for the TR-8 velocity arp.