musicianstool.com DSP Acoustic Analysis Standard

Audio Analyzer & Key Finder uses 12-tone chromagram harmonic matrices and multi-band onset transient detection to identify musical Key, 1A–12B Camelot notation, accurate tempo (BPM), and EBU R128 integrated loudness (LUFS). All DSP calculations run client-side in your browser with zero latency and full privacy.

Audio Analyzer & Key Finder Pro

Instantly detect musical key, Camelot mixing code, accurate tempo (BPM), and 60 FPS real-time FFT spectrum.100% Private — Audio files are processed locally and never uploaded to any server.

Client-Side Privacy Harmonic DSP 60 FPS Log FFT
Free Tier: 0/5 used

Drag & Drop Your Audio File Here

MP3, WAV, FLAC, M4A, OGG, AIFF — up to 100 MB

Harmonic Key Engine

Accurate Key & Camelot

Multi-band chromagram correlation eliminates relative major/minor ambiguity with high precision.

Dual-Engine Beat Tracking

Reliable Tempo (BPM)

Combines transient onset novelty curves and autocorrelation across full musical tempi.

60 FPS Log FFT

Ozone-Grade Spectrum

Real-time 20 Hz – 20 kHz logarithmic spectrum visualizer with dBFS calibration.

12-Tone Camelot Harmonic Transition Table

Camelot notation, fundamental root frequencies (A4 = 440 Hz standard), and harmonic DJ mixing routes for all 24 musical keys.

Camelot (Minor)Minor Key NameCamelot (Major)Relative Major KeyRoot Frequency (Hz)Energy Boost (+1)Energy Drop (-1)
1AAb Minor (G#m)1BB Major207.65 Hz2A12A
2AEb Minor (D#m)2BF# Major (Gb)155.56 Hz3A1A
3ABb Minor (A#m)3BDb Major (C#)116.54 Hz4A2A
4AF Minor4BAb Major (G#)174.61 Hz5A3A
5AC Minor5BEb Major (D#)130.81 Hz6A4A
6AG Minor6BBb Major (A#)196.00 Hz7A5A
7AD Minor7BF Major146.83 Hz8A6A
8AA Minor8BC Major220.00 Hz9A7A
9AE Minor9BG Major164.81 Hz10A8A
10AB Minor10BD Major123.47 Hz11A9A
11AF# Minor (Gbm)11BA Major185.00 Hz12A10A
12AC# Minor12BE Major138.59 Hz1A11A
BROADCAST & MASTERING STANDARDSNative VST3 / AU for macOS

Monitor True-Peak & LUFS Loudness Directly in Your DAW

Ensure streaming compliance with HORIZON (ITU-R BS.1770-4 / EBU R128 Radar), clean resonances with STILL Dynamic DeResonator, and balance harmonics with FIBONACCI EQ.

Explore All 21 Plugins ($49.99)

How Audio Key & BPM Analysis Works

Identifying the musical key and tempo (BPM) of a track is essential for DJs, producers, and remixers. Our Audio Analyzer processes your files entirely in your browser using the Web Audio API — nothing is uploaded to any server, ensuring complete privacy and security.

Key Detection: How It Works

Key detection uses a technique called chromagram analysis. The algorithm breaks the audio into short frames, identifies the energy of each of the 12 pitch classes (C, C#, D, D#, E, F, F#, G, G#, A, A#, B), and compares the resulting "pitch profile" against known templates for all 24 Major and Minor keys. The best match determines the detected key.

  • Chroma Features: Spectral energy is folded into 12 bins representing each semitone, regardless of octave.
  • Profile Matching: The Krumhansl-Kessler key profiles (derived from listener perception studies) are compared with the audio's chroma profile using correlation.
  • Camelot Conversion: Once the key is identified, it's mapped to its Camelot Wheel code for easy harmonic mixing reference.

BPM Detection: The Science of Tempo

BPM detection works by analyzing the audio's onset strength envelope — essentially a signal that spikes whenever a new note, drum hit, or transient occurs. The algorithm then uses autocorrelation to find repeating patterns in these onsets, identifying the dominant periodic interval which corresponds to the tempo.

Our analyzer provides not just the primary BPM but also half-time and double-time alternatives, since certain genres (like Drum & Bass at 170 BPM or half-time Hip-Hop at 85 BPM) can be interpreted at different tempo multiples.

File Upload vs. Browser Audio Capture

Our analyzer supports two modes:

  • File Upload: Drag and drop or select an audio file (MP3, WAV, FLAC, OGG, M4A). Processing happens entirely in your browser — your files never leave your device.
  • Browser Audio Capture: Capture audio playing in another browser tab (e.g., YouTube, Spotify Web Player, SoundCloud) using the browser's screen/tab sharing API. This lets you analyze any streaming audio without downloading it.

Why Privacy Matters

Unlike many online analyzers that upload your files to remote servers, Musicianstool's Audio Analyzer runs entirely client-side. Your audio data never leaves your device. This is especially important for producers analyzing unreleased tracks, stems, or works-in-progress that shouldn't be shared with third parties.

Frequently Asked Questions

How accurate is the key detection?

Accuracy depends on the complexity of the track. Songs with clear harmonic content (vocals, chords, melodies) are detected with high confidence (~85-95%). Heavily percussive tracks or atonal music may produce lower confidence scores.

What file formats are supported?

Any format your browser can decode: MP3, WAV, FLAC, OGG, M4A, AAC, and WebM audio. The Web Audio API handles decoding natively.

Is my audio uploaded to any server?

No. All processing happens 100% locally in your browser. Your audio files are never transmitted, stored, or shared with anyone. This is a core privacy guarantee of Musicianstool.

Audio Key & BPM Analyzer - Find Key & Tempo | Musicianstool