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Diapason and Mixtape

Two music discovery apps. Diapason runs artist battles to find what you actually like; Mixtape turns a year and a mood into an era-accurate playlist.

details

status
in progress
group
music
stack
Node.js, Express, Spotify Web API, YouTube Data API, an LLM as the curation engine
since
2026-08

readme

Two apps built around real catalog music (Spotify and YouTube), as opposed to my AI-generated library.

Diapason: discovery

You pit artists against each other in head-to-head battles, then react to scenes. The artists that survive become a "letter" of recommendations. Spotify checks every song and artist so nothing is made up, and YouTube supplies embeds.

Mixtape: memory

Pick a year and swipe through six moods, and you get a roughly 20-song tape from that era. It's meant to sound like what was actually on the radio, not a modern "best of".

The architecture

Both use a session-as-engine pattern. The web app writes a job request to disk, an AI session picks it up and writes back structured candidates, and the app's own engine.js applies the deterministic curation rules and validates every pick against Spotify. The model proposes; the code decides what's real and what makes the cut.

Two more experiments are in the same folder: PerfectLoops (finds seamless loop points in a song) and Bootleg (lines movie dialogue up over full-length songs).