monolith

monolith is a single-page browser instrument with two modes: an ARP that drives a rich monophonic synth voice from a step-sequencer, and a JAM "practice band" — bass, chords and drums playing real progressions over selectable style grooves, with the harmony expressed scale-relative (roman numerals) so you can solo over it in any key. Under the hood it is strictly one-directional and signal-driven (Pattern → Track → Voice): a persistent zero-alloc voice pool, FM synthesis with a per-trigger modulator-index envelope, drift LFOs and a master-bus glue chain, all tuned to stay under Firefox's render-thread deadline. Drums run a dual synth + CC0-sample pipeline; a modal-fidelity validator flags borrowed chords and a fretboard progress-ring forewarns the next change. Ships from one bundle to web (PWA), desktop (Electron) and mobile (Capacitor).