Audio analysis: BPM, key and energy

Catalyst listens to every recording you add and fills in its tempo and key, so you can filter and sort by them. Correct any value and yours is kept for good.

When audio arrives (uploaded, delivered or imported), Catalyst analyses it as soon as the file has been processed for streaming. While it works, the version shows Detecting BPM and key…. Analysis runs on Catalyst's own infrastructure; your audio isn't sent to an outside analysis service.

What's detected#

BPM: Tempo, shown as a whole number.
Key: Key and mode, written one way for each note: C, C#, D, Eb, E, F, F#, G, Ab, A, Bb, B, shown as “A minor” or “Bb major”. A song in Db shows as C# major.
Energy: 0 to 1: how loud and how busy the recording is. A rough guide for sorting by feel, not a measure you can compare with other services. Mastering raises it, so a work tape reads lower than its master.
Loudness and danceability: Measured and stored for later use.

Each version is analysed separately, because a work tape and a master can differ in tempo and key. The Library uses the primary version's values. Only the first 10 minutes of a file are analysed, and very short or silent files get no BPM or key.

Correct a value#

Detection is good, not perfect: half-time feels and ambiguous keys trip it up. On the song's Versions tab, click the BPM or key on any version and type or pick the right value. It saves automatically.

A value you enter is marked Entered by a person; a detected one, Detected from the audio.
Your value always wins, in filters, sorting and everywhere else. Re-analysing never overwrites it.
Every change is recorded in the song's History.

To run detection again on a version (for example after replacing its audio), choose ⋯ → Detect BPM & key again.

Analyse songs you already had#

Audio added before analysis existed, or files that failed, can be analysed in one go. Settings → Audio analysis shows how many files are analysed, in progress, not analysed yet or couldn't be analysed. An owner can choose Start analysis: Catalyst shows how many files and the estimated cost, and starts only when you confirm. Nothing is analysed in bulk without that confirmation.

Mood and genre tags#

Suggested mood, genre and instrumentation tags, and “find songs like this one”, are being tested with our first publisher and aren't generally available yet. When they arrive, AI-suggested tags will stay visibly separate until someone on your team confirms them.

Something unclear or missing? Email support@joincatalyst.io.