Squeezebox Studio
Scale

D major on a B/C button accordion

D major uses D, E, F♯, G, A, B and C♯. On a B/C there is one complete octave, from D4 to D5.

From D4 to D5

Push, above the linePull, below the line

No single row has every note of this octave, so you have to cross between the rows. This is the way with the fewest changes of bellows: two going up, and four moves between rows.

C rowinsideE3A31'G3B32'C4D413'E4F44'G44A455'C5B466'E5D587'G5F58'C6A59'E6B510'B rowoutsideD♯3G♯31F♯3A♯32B3C♯43D♯4E424F♯43G♯45B4A♯46D♯5C♯577F♯5E58B5G♯59D♯6A♯510F♯6C♯611
The same way, marked on the box: numbers give the order, blue halves are push and orange are pull.
Every button for each note of this octave
NoteButtons
D43′ pull
E44 pull, 4′ push
F♯45 push
G45′ push
A45′ pull
B46 push, 6′ pull
C♯57 pull
D57′ pull

Above and below

From D3 the scale is incomplete: this box has no D3. Tunes that go that far down will need a different note there, or a different key.

From D5 the scale is incomplete: this box has no D6. Tunes that go that far up will need a different note there, or a different key.

Tab is only the start

A scale shows where the notes are, but a tune rarely runs straight up the octave. Whether you play a note on the push or the pull depends on the notes either side of it, the rhythm, and whether you play along the rows or across them. Along or across the rows explains the difference.

Same notes, different home: B minor, E Dorian, A Mixolydian.

D major on other boxes: D/G melodeon.

Other keys on a B/C: G major, A major, C major, F major, E major, E minor, A minor, B minor, D minor, G minor, A Dorian, E Dorian, D Dorian, B Dorian, G Dorian, D Mixolydian, A Mixolydian, G Mixolydian, C Mixolydian. Or see every key compared and the B/C button chart.