All stages · Demo 105

Pitch desk

Choice A4 / C4 / E2. Equal temperament is `440 * 2 ** ((midi-69)/12)`. Jev does not do logs.

ChoicePitch → frequency in code

A piano strip. Concert A lights magenta; the number under it is physics in JS.

replaynote —hz —

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STANDBY

All 4056 stages

Educational stage on jev.page — not the official TypeSafe console. Live calls go to POST https://api.typesafe.ai/v1/systemone from your browser when you paste a key. Without a key, the stage plays a recorded decision shaped like jev-1.13.0. Jev does not write the UI copy.