TempoPeek

The circle of fifths

Keys are arranged by signature: each step clockwise adds a sharp. Pick a key and four light up — the relative, which shares its signature exactly, the two a fifth either side, which differ by one accidental, and the parallel, which keeps the tonic and swaps the mode. That is the whole of what a mixing wheel encodes, with the relations named instead of numbered.

C — no sharpsCno sharpsG — 1 sharpG1 sharpD — 2 sharpsD2 sharpsA — 3 sharpsA3 sharpsE — 4 sharpsE4 sharpsB — 5 sharpsB5 sharpsF♯ — 6 sharpsF♯6 sharpsD♭ — 5 flatsD♭5 flatsA♭ — 4 flatsA♭4 flatsE♭ — 3 flatsE♭3 flatsB♭ — 2 flatsB♭2 flatsF — 1 flatF1 flatAm — AmEm — EmBm — BmF♯m — F♯mC♯m — C♯mG♯m — G♯mE♭m — E♭mB♭m — B♭mFm — FmCm — CmGm — GmDm — Dm

Selected key

C major — no sharps and no flats

Fits with

The commercial wheel sold for DJ software puts a number and a letter on each of these segments. The numbering is a trademark, and it carries no information the names do not: a relative key shares the signature, a dominant is a fifth up, a subdominant a fifth down, a parallel keeps the tonic and swaps the mode.