Diminished tuning

Diminished tuning is a system of choosing the reeds for a diatonic wind instrument (such as a harmonica or accordion) in which the blow notes repeat a sequence of

C E♭ F♯ A

and draw notes follow a repeating sequence of

D F G♯ B

(perhaps shifted to begin with E♭ and F, with F♯ and G♯, or with A and B).

For example:

hole  1  2  3  4  5  6  7  8  9 10 11 12
blow note C E F A C E F A C E F A
draw note D F G♯ B D F G♯ B D F G♯ B

See also