What Is Open Key Notation?

Open Key notation is a way of writing musical keys as a number from 1 to 12 followed by m for minor or d for major, arranged so that adjacent numbers are harmonically compatible. It is the system Traktor uses. It encodes exactly the same relationships as the Camelot wheel, but with a different numbering: Open Key 1m is A minor, which Camelot calls 8A.

The two systems side by side

Musical key	Camelot	Open Key
A minor / C major	8A / 8B	1m / 1d
E minor / G major	9A / 9B	2m / 2d
B minor / D major	10A / 10B	3m / 3d
F-sharp minor / A major	11A / 11B	4m / 4d
D-flat minor / E major	12A / 12B	5m / 5d
A-flat minor / B major	1A / 1B	6m / 6d
E-flat minor / F-sharp major	2A / 2B	7m / 7d
B-flat minor / D-flat major	3A / 3B	8m / 8d
F minor / A-flat major	4A / 4B	9m / 9d
C minor / E-flat major	5A / 5B	10m / 10d
G minor / B-flat major	6A / 6B	11m / 11d
D minor / F major	7A / 7B	12m / 12d

Converting between them

Camelot to Open Key: add 5 to the number, wrap past 12, swap A for m and B for d.

Open Key to Camelot: subtract 5 from the number, wrap below 1 by adding 12, swap m for A and d for B.

The relationships are identical. In both systems the same number with the other letter is the relative major or minor, and one number up or down is a fifth away.

Why two systems exist

Camelot was introduced by Mixed In Key and adopted by rekordbox, Serato and most DJ-facing tools. Native Instruments introduced Open Key for Traktor with 1 placed at A minor and C major, which many musicians consider the simplest keys. Neither is better; they are two labels for the same wheel. Problems only arise when a DJ moves between Traktor and another application and forgets to convert.

How Club Ready Music writes keys

Club Ready Music writes the key of a generated track in all three forms so each application finds one it understands:

• The musical name, such as Am or F#, in the standard ID3 key frame. Traktor, rekordbox, Serato, VirtualDJ, Engine DJ and djay all read this.
• The Camelot code, such as 8A, in a text frame named INITIALKEY.
• The Open Key code, such as 1m, in a text frame named OPENKEY.

The comment tag, the cue sheet in the DJ pack and the rekordbox XML repeat the Camelot and Open Key codes with the musical name, so you can read the key in any browser even if the application only shows one notation. Traktor users can disable key re-analysis and trust the tag.