How to read the wheel
Twelve numbers around a clock, two rings. The inner ring is minor keys and carries an A; the outer ring is major keys and carries a B. 8A is A minor, 8B is C major, and the reason they sit together is that they are the same seven notes — a relative pair. That is the whole trick of the wheel: it rearranges keys so that the ones that share notes end up next to each other, and you can find a mix without knowing any theory.
Click any key and the ones it mixes with light up, each labelled with what kind of move it is. The labels matter more than the highlighting: every one of these is a valid mix, but they do different things. Some hold the room where it is, some lift it, some let it down on purpose. Picking between them is the actual decision, and it depends on where you are in the set rather than on the keys.
What each kind of move does
The safest is the same key or its relative: nothing clashes, and the room does not register a change at all. One step around the wheel in either direction is nearly as safe and does something useful — clockwise adds a little tension, anticlockwise lets a little out. These are the moves you can make on a whim mid-set without listening first.
Bigger jumps up the wheel are audible. They work, but the room hears them as a lift, so they want a moment that justifies one — a drop, a break, a track everyone recognises. The same distance downward releases pressure, which is how you open space after a peak without simply turning the energy off. And moving between the rings at the same number is the mood change: minor to major, the tempo unchanged, the whole feeling of the room turning over.
What the wheel does not show is anything that is not in the table. A key that stays dark is not forbidden — DJs break this constantly and on purpose — but it is a move you should hear before you trust it, rather than one the wheel is telling you is safe.
Camelot, Open Key and musical notation
Three ways of writing the same twenty-four keys, and your library probably has more than one. Camelot is Mixed In Key's system and the one most DJs say out loud. Open Key is Traktor's: the same wheel rotated, so Camelot 8A is Open Key 1m. Musical notation is what the rest of the world uses — A minor, or Am.
The table below has all twenty-four in all four columns, and it is in the page itself rather than drawn by JavaScript, so you can search it, print it or read it on a phone with a bad connection in a booth. The calculator on the next page accepts any of the three notations without being told which one you typed.
Where the wheel stops helping
Two tracks in compatible keys can still sound wrong together, and the wheel has no opinion about why. Tempo is the obvious one. Energy is the less obvious one: a perfectly matched key between a sparse intro and a peak-time roller is still a mix the room feels as a lurch. And key tags are often wrong — detection software disagrees with itself, and a tag nobody checked is a guess with a number on it.
That is what the other two tools are for: the checker adds the tempo half of the question for two specific tracks, and the set analyser reads the energy of a whole tracklist at once.