Free Harmonic Mixing Wheel with Compatible Keys

How Camelot numbers and letters work

The Camelot wheel is a chart of the 24 musical keys arranged like a clock face. Each key gets a number from 1 to 12 and a letter, A for minor and B for major, so A minor is 8A and C major is 8B. Two keys that share a number, or sit one hour apart on the same ring, mix without clashing.

The system was invented by the DJ Mark Davis and is part of the Mixed In Key software. It replaces key names such as “F♯ minor” with a code a DJ can read in a dark booth and compare with simple arithmetic.

Moving one step clockwise raises the key by a perfect fifth, seven semitones. Moving one step counterclockwise lowers it by a fifth. The letter switch keeps the number and swaps a minor key for the major key that uses the same notes.

Camelot key chart with key signatures

Each number on the wheel pairs a minor key with its relative major. The two keys of a pair share a key signature, the sharps or flats written at the start of a score, so they use the same seven notes.

Read down the last column and the pattern of the wheel appears. Each step clockwise adds a sharp or removes a flat, which changes one note of the scale. That single changed note is why neighbors on the wheel blend.

Traktor and some other software write keys in Open Key notation, which uses the same wheel with different labels: “d” for major, “m” for minor, and C major at 1d. To convert Open Key to Camelot, add 7 to the number, subtract 12 if the result is above 12, and change m to A or d to B. 1m becomes 8A and 6d becomes 1B.

Compatible moves from a single key

Pick a key above and the wheel highlights five kinds of move. The table shows them from 8A, A minor, with the number of scale notes that change on the way.

The same code is the safest mix there is. Two tracks in 8A can play over each other for a long blend, and their melodies and bass lines usually fit together.

One step around the ring is the move most harmonic sets are built from. Going clockwise tends to feel like a lift, and counterclockwise like settling down, because the new key sits a fifth above or below the old one.

The letter switch keeps every note and changes the mood. Moving from A minor to C major usually sounds brighter, and the reverse sounds darker, while the two tracks still share all seven notes.

Energy boosts with +2 and +7

+2 on the same ring raises the key by a whole step, two semitones. From 8A that is 10A. Two notes of the scale change, so the mix is less smooth than ±1, and the jump in pitch reads as a rise in energy. It works best when the outgoing track drops to drums or a breakdown first.

+7 on the same ring raises the key by one semitone, the same kind of key change many pop songs make before the last chorus. From 8A that is 3A. Five notes change, so a long blend will clash. Use it as a quick cut or a short transition over drums, and the new track will sound noticeably higher and brighter.

Moves the wheel leaves unmarked

Some DJs also use the diagonal move, from 8A to 9B or from 8B to 7A. 9B, G major, uses the same notes as 9A, so it changes one note from A minor, but it also changes the mood. The wheel above does not highlight it, so test it by ear before you rely on it.

Anything further away, such as 8A to 5A or 8A to 2B, changes several notes at once. These mixes need a transition that hides the change: a drum break, an echo out, or a hard cut on the downbeat.

Why neighboring keys blend

The Camelot wheel is the circle of fifths with friendlier labels. Musicians have used that circle for centuries to show which keys are closely related, and the relationship is the number of notes two keys share.

Keys a fifth apart share six of their seven notes. When two tracks in those keys play together, almost every note of one fits the scale of the other, and the one note that differs passes by without a harsh clash.

A minor key and its relative major share all seven notes and differ only in which note feels like home. That is why the letter switch changes the color of a mix while every note still fits.

Keys across the wheel share few notes. Bass lines and chords then fight each other, and the result sounds out of tune even when both tracks are in perfect tune on their own.

Building a DJ set by key

1. Tag the key of every track before the gig. Most DJ software detects keys on import. For a single song, the key finder shows the key, its Camelot code and the BPM, and opens the result on this wheel.
2. Sort or filter the library by key. With Camelot codes, tracks in neighboring keys sit next to each other in a sorted list.
3. Plan the shape of the set. Long runs of ±1 moves keep a mix smooth. Save +2 and +7 for the moments you want the room to lift.
4. Match tempo as well as key. Two tracks in compatible keys still need matching tempos to blend. The BPM finder reads the tempo of a file in the same way.
5. Rehearse the risky transitions. Play the blends you have never tried in headphones first.

Checking a detected key by ear

Key detection reads the notes that dominate a recording, and it can be wrong. Its errors usually land on a closely related key: the relative key, such as C major reported as A minor, or a neighbor a fifth away. Both share most of their notes with the true key, so a mix based on the wrong tag usually still works.

Tracks with few pitched notes, heavy distortion or a key change halfway through give the least reliable results. If a blend sounds sour, trust your ears over the tag, and play the bass line of each track against the other to hear where they disagree.

When key matters more, and when less

Key matters most when two tracks play pitched parts at the same time for a long time. A vocal over another track’s chords, two melodies, or two bass lines will expose any clash within a bar.

• Drum-only intros and outros have little pitch, so they mix with almost any key.
• Quick cuts never play both tracks at once, so the keys never meet.
• Breakdowns let you remove the bass of one track before the next one brings in its key.
• Acapellas and vocal loops are the strictest case. Keep them in the same key or a ±1 neighbor.

A set that only follows safe moves can sound flat after an hour. Energy, genre and the crowd count as much as key, and many good transitions break the wheel on purpose.

Changing a track’s key with pitch and key lock

The tempo fader on most decks changes speed and pitch together, like a turntable. Raising a track by about 6% raises it by about one semitone, because each semitone is a frequency ratio of about 1.0595. On the wheel, every semitone up is +7 and every semitone down is −7.

Small tempo nudges of 1–3% move the pitch by less than a semitone. The track then sits slightly sharp or flat of its tagged key, and a long blend with a track in the same key can sound a little out of tune.

Key lock keeps the original pitch while you change the tempo, so the Camelot code stays the same. Free DJ software such as Mixxx detects the key of each track, shows it in the library and the decks, and has a key lock button on every deck. Some decks also shift the key in semitone steps, which lets you move a track onto a compatible code before you mix it in.

Key matching for producers

The same wheel helps outside the DJ booth. A vocal sample, a loop or a bass line taken from another track will sit in your song without pitch correction if its key is the same as your song’s, or one step away.

Loop and sample packs usually tag each file with its key. Look the key up on the wheel before you drag a loop into a project, and choose loops from the highlighted keys. The guide to writing a topline with loops and beats shows the process from a loop to a finished melody.

When a sample sits in the wrong key, shift its pitch in semitones and count the move on the wheel. How to change speed, tempo and pitch in Audacity covers both the pitch-only and the speed-and-pitch methods.

The wheel also helps to order an album or an EP. Tracks that share a number or sit next to each other flow from one to the next, and a bigger jump between two tracks marks a deliberate change of mood.