henrikhank post_id=55283 time=1518109622 user_id=2321 said:
How the...do you play Bbdim (Bb-C#-E) on accordion?
Two ways spring to mind, assuming you have a standard, 6 buttons-per-row accordion (2+4 configuration).
The first thing Id try is just to play it as a full Bb dim7 chord, using the dim button on the Bb row. Often lead sheets--particularly in the jazz idiom--will notate a chord as the simplest form of the chord that gets the point across. But that doesnt mean you cant add more notes to the chord if that makes sense given the harmony of the piece. (In jazz, in fact, youre
expected to do this.) So try it and see if it sounds okay.
If that doesnt work, and you really need just a Bb dim triad, try using the C# dim chord button with the counterbass of F# (which is A#), or use the Db dim chord button with the counterbass of Gb (which is Bb).
If your accordion is like most, it leaves out the third note of the diminished 7th chord (which is the flat-fifth). So a C#dim7, which should be C#, E, G, Bb, really winds up just being C#, E, Bb. (Same for the Db dim.)
Edited to add a third idea: Dont play a chord button in the left hand at all. Just play the Bb bass note. Fill in the Bb dim chord in the right hand if you feel the tune needs it.