KeySense

KeySense is an offline music analysis tool for musicians, DJs, producers, and serious listeners. It estimates the musical key, tempo (BPM), and Camelot wheel position of whatever you are listening to — entirely on your device, with no uploads and no account.

Start an analysis manually. Choose microphone input to listen to a live source, or use device playback capture to analyze whatever is playing on your phone (where Android allows it). Within seconds, KeySense returns a stable estimate of key, BPM, confidence, and a set of professional summary metrics.

PRIVACY FIRST

KeySense was designed around a single principle: your audio is yours. All analysis runs on the device. Raw microphone audio is never uploaded and never saved. Raw playback audio is never uploaded and never saved. The app does not require an account, does not show ads, and does not include third-party trackers.

If you turn on local history, KeySense stores only analysis summaries — key, BPM, confidence, input source, and a timestamp. You can disable history or clear it from Settings at any time.

KEY DETECTION

KeySense uses a 24-key major and minor model with dual-profile correlation (Krumhansl-Schmuckler and Temperley) and bass weighting tuned for popular music, electronic music, and acoustic genres. The Camelot wheel position is shown next to every result, making KeySense compatible with DJ software conventions used by Mixed-In-Key, Rekordbox, Serato, and Traktor.

TEMPO AND BEAT TRACKING

Tempo estimation runs an ONNX inference model (BeatNet) on the device, paired with a conservative octave correction stage to avoid common half-time and double-time errors. The result is a stable BPM and a confidence score you can trust before mixing or transcribing.

PROFESSIONAL DETAILS

A dedicated Details screen shows the chroma overview, diagnostic metrics, and the analysis window so you can verify what the app is doing rather than treating it as a black box.

CORE FEATURES

- Offline key and BPM detection
- Camelot wheel display for DJ workflows
- Microphone capture and supported device playback capture
- Confidence-aware results, including an uncertain state when the input is too short or too noisy
- Professional details: chroma overview, beat tracking diagnostics, analysis window
- Local-only history of analysis summaries
- CSV and shareable text export of results
- Material 3 design with light, dark, and Material You dynamic theming
- Chinese and English interface

WHO IT'S FOR

- DJs preparing harmonic mixes who want a fast, private second opinion on key and BPM
- Producers checking the key of a sample, loop, or stem before sound design
- Songwriters and instrumentalists transcribing songs by ear
- Music students learning key and tempo recognition
- Anyone who simply wants to know the key and BPM of what is playing without sending audio to a server

NOTES

Device playback capture depends on Android system support and on whether the source app allows being captured. If a particular source blocks capture, switch to microphone mode and play the audio out loud.

KeySense is built natively for Android and runs efficiently on modern phones and tablets. It targets Android 12 and above and ships with full 64-bit and 16 KB memory page support for Android 15+ devices.

CONTACT

For questions or feedback, contact: contact@matrixreligio.com