KeyLock listens to whatever you play — a sample, loop, melody, vocal, 808 line or MIDI clip — and names the key the way producers write it: B♭ minor, with the A♯ minor equivalent or the key signature next to it. Every result comes with a confidence meter: when the material is ambiguous, KeyLock says so instead of guessing, and relative keys (E minor / G major) are shown as "same notes". Detection uses the same detector as the DarkPlugins App, tested on real recordings with known keys. Audio and MIDI pass through untouched — the plugin never retunes anything. Analyse a live window of 6–40 seconds or the whole song, or press CAPTURE to analyse an exact passage (with SYNC it follows PLAY and STOP in your DAW); HOLD freezes the result. The key map shows everything you've played and catches key changes. The Loop, Melody, Vocal and 808 / Bass profiles tune the analysis to the material — bass lines get a dedicated pitch tracker, because a spectrum can't see the lowest 808 notes. When the host sends MIDI, KeyLock reads the key straight from the notes. KEY LOCK locks your beat's key and checks every new sample against it: how many notes fit, which ones fall outside the key and how many semitones to shift the sample so it sits. Plus a circle of fifths with the fit of all 24 keys, the pitch-class distribution, scales that fit the material, related keys (click to lock), a chromagram with a keyboard and a chromatic tuner with A4 from 415 to 466 Hz. Free for everyone with a DarkPlugins account.