arpgen is an original transport-synced MIDI arpeggiator with two source
modes:
- Chord captures incoming note-ons into quarter-, half-, or whole-bar slices and arpeggiates the most recently completed non-empty slice.
- Scale continuously derives scale runs, triads, or sevenths across one to four octaves. With no held notes it uses the selected key's tonic near middle C; held notes temporarily replace that internal register anchor.
Both modes share quarter through thirty-second note rates, including eighth- and sixteenth-note triplets, plus up, down, up/down, and down/up traversal. Alternating orders do not repeat their endpoint notes.
See docs/design.md for the musical and transport decisions.
The DPF/VST3 wrapper exposes a silent stereo output bus for compatibility with hosts that reject event-only plugins with no audio outputs. The portable core remains MIDI-only, and the wrapper clears both output channels every block.