A track’s BPM and key: why you need them and how the Camelot system works
BPM and key are often seen as technical data for DJs. But they’re useful to the artist too: when looking for a vocalist, sending a beat to an artist, putting together an EP where the tracks should flow into each other, and even when choosing a streamer. Let’s look at what these numbers mean and how to use the Camelot wheel.
In short
- BPM is the number of beats per minute; analyzers sometimes show half or double the tempo.
- The key is the home note and the mode (major or minor); every minor key has a relative major with the same notes.
- Camelot codes the 24 keys as a number from 1 to 12 and a letter: A is minor, B is major.
- They mix harmonically: the same code, a neighboring number with the same letter, the same number with the other letter.
- Automatic key detection is an estimate, not the truth: check it by ear.
Contents
BPM: the track’s tempo
BPM (beats per minute) is how many beats fit into a minute. It’s the main parameter of the groove: it decides which music the track fits next to in a playlist, whether it works for a dance floor and how densely you can rap over the beat. Typical genre ranges:
| Genre | Typical tempo |
|---|---|
| Hip-hop, boom bap | 80–100 BPM |
| Trap | 130–150 BPM (feels like 65–75) |
| House | 118–128 BPM |
| Techno | 125–140 BPM |
| Drum and bass | 170–176 BPM |
| Pop | 90–130 BPM |
Key: the home note and the mode
The key is the home note (the tonic) and the mode: major or minor. “A minor” means the music gravitates towards the note A and sounds in a minor mode. Every minor key has a relative major made up of the same notes: for A minor it’s C major, for E minor it’s G major.
Why an artist needs to know their track’s key:
- Vocals. A vocalist or topliner needs to know whether the key suits their range.
- Collaborations and samples. To add a part, a sample or an acapella, you need to be in key or transpose on purpose.
- Track order on a release. Transitions between neighboring tracks on an EP sound more natural when their keys are compatible.
- Pitching. Many curators, labels and DJs filter tracks by tempo and key.
The Camelot wheel: keys as a code
The Camelot system, created by DJ Mark Davis, turns the circle of fifths into a clock. Each of the 24 keys gets a number from 1 to 12 and a letter: A is minor, B is major. Relative keys share a number: 8A is A minor, 8B is C major. Neighboring numbers are a fifth apart, which means they have almost the same set of notes.
| Code | Minor (A) | Code | Major (B) |
|---|---|---|---|
| 1A | A♭ minor | 1B | B major |
| 2A | E♭ minor | 2B | F♯ major |
| 3A | B♭ minor | 3B | D♭ major |
| 4A | F minor | 4B | A♭ major |
| 5A | C minor | 5B | E♭ major |
| 6A | G minor | 6B | B♭ major |
| 7A | D minor | 7B | F major |
| 8A | A minor | 8B | C major |
| 9A | E minor | 9B | G major |
| 10A | B minor | 10B | D major |
| 11A | F♯ minor | 11B | A major |
| 12A | C♯ minor | 12B | E major |
Which keys go together
Four rules are enough for most tasks. Take a track in 8A as an example:
- The same code — 8A. A perfect match.
- A neighboring number, the same letter — 7A or 9A. They differ by one note, and the transition sounds smooth.
- The same number, the other letter — 8B. The same notes, but the mood changes from minor to major.
- An energy boost — +7 around the wheel (8A → 3A) raises the key by a semitone, +2 (8A → 10A) by a whole tone. Sharper, but effective if done on purpose.
These rules describe harmonic compatibility, not quality. A track in an “incompatible” key can sit perfectly next to another if the transition is built by the arrangement. Camelot is a hint, not a ban.
Why analyzers get it wrong
Key detection is a statistical estimate: the algorithm looks at which notes sound more often and for longer, and compares that with templates. So the typical mistakes are predictable:
- It confuses relative keys (8A and 8B): the set of notes is the same.
- It confuses a key with its neighbor a fifth away (8A and 9A), especially in tracks with simple harmony.
- It gets lost in tracks with modulation, atonal sound design or badly detuned samples.
- It gets short fragments wrong — analyze the whole track.
The most reliable check is to play the tonic on a keyboard over the track and listen for where the music “settles”.
How to find tempo and key by hand
Tempo. If the track was made in a DAW, the tempo is already saved in the project — that’s the most accurate source. For someone else’s track or an old recording, the “tap” method works: turn on tap tempo in your DAW or any online metronome and tap a key along with the kick for 15–20 seconds. Round the result to a whole number and check whether the metronome stays with the track for a minute: if it drifts, the tempo is fractional or “floating” (normal for live recordings).
Key. Start with the bass: find the note on the keyboard where the bass “comes to rest” at the end of phrases and in the last bar of the chorus. That’s your candidate for the tonic. Then play a minor and a major triad on that note over the track — the one that doesn’t grate on the ear gives you the mode. If neither fits, try the relative key: it has the same notes but a different home.
BPM and key on stream
On Stream-Q the tempo and the key with its Camelot code are detected for every uploaded file and shown to the streamer in the queue as a badge like A minor · 8A. The “Track card” overlay shows viewers the BPM, key, file quality and progress with the sections marked — intro, verse, chorus, drop. These values aren’t counted as errors: they’re reference information. What else to check before sending is collected in the checklist for artists, and how the overlays look on air — on the page for streamers.