the camelot wheel is the standard harmonic mixing reference: pick a key, and the same-number, plus-minus-one and relative-major rules tell you which other keys blend cleanly. this version adds the advanced moves - energy boosts, the diagonal, jaws - as toggleable overlays.

check bpm covers the other half of mixing math: tempo. tap along to a track to find its bpm, and the tool shows half, double and dotted-eighth equivalents - the ratios that let hip-hop mix into drum and bass or house cross into 170 territory without pitching either track.

check db answers the question you should ask before plugging in: how loud is it in here? hold up your phone and it reads the room on an lcd display - a-weighted, calibrated, nothing recorded or uploaded.

more tools land here as they get built. each is a standalone repo, deployed from a raspberry pi in my apartment.