What keys can a G/C melodeon play in?
Without the accidental buttons, a G/C has a full octave in C and G major, and in A and E minor. The accidentals add a few more, one octave at a time.
The tables below check every key against the buttons on a 21-key G/C with the layout in the G/C chart. A key counts as playable when every note of one octave of its scale is on the box, starting from the key note.
Major keys
| Key | Notes | Complete octave |
|---|---|---|
| C major | C D E F G A B | From C4 and C5 |
| G major | G A B C D E F♯ | From G3 and G4 |
| D major | D E F♯ G A B C♯ | Short of E3 in the best octave |
| A major | A B C♯ D E F♯ G♯ | From A3, using 2 accidental notes |
| E major | E F♯ G♯ A B C♯ D♯ | Short of E3 and G♯3 in the best octave |
| B major | B C♯ D♯ E F♯ G♯ A♯ | From B3, using 4 accidental notes |
| G♭ major | G♭ A♭ B♭ C♭ D♭ E♭ F | Short of A♭3 and B♭3 in the best octave |
| D♭ major | D♭ E♭ F G♭ A♭ B♭ C | Short of D♭5 in the best octave |
| A♭ major | A♭ B♭ C D♭ E♭ F G | Short of A♭3 and B♭3 in the best octave |
| E♭ major | E♭ F G A♭ B♭ C D | Short of E♭5 in the best octave |
| B♭ major | B♭ C D E♭ F G A | Short of B♭3 in the best octave |
| F major | F G A B♭ C D E | From F4, using an accidental note |
Minor keys
| Key | Notes | Complete octave |
|---|---|---|
| A minor | A B C D E F G | From A3 and A4 |
| E minor | E F♯ G A B C D | From E4 and E5 |
| B minor | B C♯ D E F♯ G A | From B3, using an accidental note |
| F♯ minor | F♯ G♯ A B C♯ D E | Short of G♯3 in the best octave |
| C♯ minor | C♯ D♯ E F♯ G♯ A B | Short of C♯5 in the best octave |
| G♯ minor | G♯ A♯ B C♯ D♯ E F♯ | Short of G♯3 and A♯3 in the best octave |
| E♭ minor | E♭ F G♭ A♭ B♭ C♭ D♭ | Short of D♭5 and E♭5 in the best octave |
| B♭ minor | B♭ C D♭ E♭ F G♭ A♭ | Short of B♭3 in the best octave |
| F minor | F G A♭ B♭ C D♭ E♭ | Short of D♭5 and E♭5 in the best octave |
| C minor | C D E♭ F G A♭ B♭ | From C4, using 3 accidental notes |
| G minor | G A B♭ C D E♭ F | Short of B♭3 in the best octave |
| D minor | D E F G A B♭ C | From D4, using an accidental note |
Dorian
| Key | Notes | Complete octave |
|---|---|---|
| D Dorian | D E F G A B C | From D4 and D5 |
| A Dorian | A B C D E F♯ G | From A3 and A4 |
| E Dorian | E F♯ G A B C♯ D | Short of E3 in the best octave |
| B Dorian | B C♯ D E F♯ G♯ A | From B3, using 2 accidental notes |
| F♯ Dorian | F♯ G♯ A B C♯ D♯ E | Short of G♯3 in the best octave |
| C♯ Dorian | C♯ D♯ E F♯ G♯ A♯ B | Short of C♯5 in the best octave |
| A♭ Dorian | A♭ B♭ C♭ D♭ E♭ F G♭ | Short of A♭3 and B♭3 in the best octave |
| E♭ Dorian | E♭ F G♭ A♭ B♭ C D♭ | Short of D♭5 and E♭5 in the best octave |
| B♭ Dorian | B♭ C D♭ E♭ F G A♭ | Short of B♭3 in the best octave |
| F Dorian | F G A♭ B♭ C D E♭ | Short of E♭5 in the best octave |
| C Dorian | C D E♭ F G A B♭ | From C4, using 2 accidental notes |
| G Dorian | G A B♭ C D E F | From G4, using an accidental note |
Mixolydian
| Key | Notes | Complete octave |
|---|---|---|
| G Mixolydian | G A B C D E F | From G3 and G4 |
| D Mixolydian | D E F♯ G A B C | From D4 and D5 |
| A Mixolydian | A B C♯ D E F♯ G | From A3, using an accidental note |
| E Mixolydian | E F♯ G♯ A B C♯ D | Short of C♯5 in the best octave |
| B Mixolydian | B C♯ D♯ E F♯ G♯ A | From B3, using 3 accidental notes |
| F♯ Mixolydian | F♯ G♯ A♯ B C♯ D♯ E | Short of G♯3 and A♯3 in the best octave |
| D♭ Mixolydian | D♭ E♭ F G♭ A♭ B♭ C♭ | Short of D♭5 in the best octave |
| A♭ Mixolydian | A♭ B♭ C D♭ E♭ F G♭ | Short of A♭3 and B♭3 in the best octave |
| E♭ Mixolydian | E♭ F G A♭ B♭ C D♭ | Short of D♭5 and E♭5 in the best octave |
| B♭ Mixolydian | B♭ C D E♭ F G A♭ | Short of B♭3 in the best octave |
| F Mixolydian | F G A B♭ C D E♭ | Short of E♭5 in the best octave |
| C Mixolydian | C D E F G A B♭ | From C4, using an accidental note |
A full octave isn't the whole story
A tune only needs the notes it actually uses. One in A major that never reaches for a G♯ won't miss one on your box, and plenty of tunes in the modes leave out a note or two. So use the tables as a guide to where a key sits comfortably, then look at the tune itself. If it still sits badly, try it a tone or a fourth away.
Squeezebox Studio does this for a whole tune: it tries the tune in every key, counts the notes your box can't play, and suggests the keys that suit it best.
Other boxes: D/G melodeon, B/C button accordion.