distilled into a prompt:
http://tibo.dog's music is synthesized live in an AudioWorklet. The chip is a Game Boy-style synth with two pulse voices, a 4-bit wave voice, a noise voice and two sound-effect voices, over a stereo synthwave bed: bass, pad, drums, sidechain ducking, ping-pong delay and reverb. The main thread turns game events into music and sound cues and posts them to the worklet, which renders every sample.
Melodies are written by hand as step-sequenced pattern lines, one token per step, played in an order list. Pulse 1 sings the lead. Pulse 2 plays the arp, a chord cycled at 60 Hz, such as C4:47 for C, E and G. The wave voice plays the counter-melody, and the bed carries the bass line and pad chords. Every song runs at 128 BPM, and the biome songs and the first boss song are versions of one main theme. Intensity brings the melody in by layers, with the lead entering at 0.5 and the counter at 0.85. Nothing generates or transposes notes at runtime.
Music plays on two decks. A plain song change is a two-bar crossfade that starts on a bar line. During a run, a DJ mixes songs like a live set. It holds each song for at least sixteen bars, starts a mix only on an eight-bar phrase, and overlaps the decks for four bars. Each song is split into stems (lead, arp, counter, bass, pad), and the stems trade decks on the swap bar. The DJ picks the mix by how closely the two songs match. Two versions of the same theme blend, layering both songs' lead, arp and pad while the bass and counter swap. Songs that share a bar grid duet, with both leads playing across the overlap while the backing changes songs. Any other pair gets a melody mix, which keeps the outgoing lead singing over the incoming backing. The lift and peak tracks are DJ takes. Each keeps its own lead, and its backing is rebuilt to match the current biome's version of the theme.
