Audio Analysis
Automatic detection of BPM, key, genre, mood, and instruments.
How It Works
When you upload audio, Locker's custom-built analysis engine automatically detects musical properties from the audio signal. Analysis runs in the background on each version you upload, so you can keep working while it processes. Once complete, the results appear in the version panel of the inspector.
Analysis uses machine-learning models trained on large music datasets. It examines tempo, harmonic content, timbral qualities, and spectral features to generate accurate metadata. These results then power Locker's filters, search, and AI features like brief matching.
What Gets Detected
Every analysed version receives the following metadata:
- BPM (Tempo): Exact beats per minute, plus alternative readings at half and double tempo for ambiguous cases
- Musical Key: Key signature and mode (e.g., C major, F# minor), with a confidence score
- Genre: Multiple genre tags ranked by confidence, so you see the primary genre and close alternatives
- Mood: Emotional character of the track, also ranked by confidence
- Instruments: Detected instruments present in the audio, sorted by prominence
- Vocal/Instrumental: Whether the track contains vocals, useful for filtering sync-ready instrumentals
- Waveform: Visual representation of the audio for quick navigation
- Duration: Precise length in seconds
Genre, mood, and instrument tags are displayed with their top predictions. You can use these in filters to find tracks that match specific criteria.
Re-Analysing
You can re-run analysis on any version at any time. This is useful if you have replaced the audio file, if analysis failed previously, or if you simply want to refresh the results with the latest model. Open the version in the inspector and click the analyse button.
Re-analysis uses one analyser credit. If you need to analyse many tracks at once, you can select multiple tracks in the library and run batch analysis from the toolbar.
Version-Level Data
Analysis data belongs to the version, not the track. This matters because different versions of the same song can have different tempos, keys, or instrumentation. A home demo might be in a different key than the studio version. A remix might have a completely different BPM.
When you view a track in the library, the displayed BPM, key, and tags come from the default version. Change the default version to update what shows in the track list.
Analyser Credits
Each plan includes a monthly allocation of analyser credits. One credit is used per version analysed. Unused credits roll over to the next month up to your plan's maximum balance, so occasional quiet months let you build a buffer for busier periods.
If you run out of credits mid-month, you can wait for the next billing cycle or upgrade your plan for a higher allocation. You can check your current balance in Profile & Settings under Plans & Billing.