Two buttons with one finger

[R Small]

Some chords I've come across playing my English concertina seem to be easier to play using one finger for two buttons. Would this be considered acceptable technique?

[MTGuru]

Sure, why not. Alistair Anderson describes the technique in his method. Classical fingerings sometimes call for 2 buttons on a finger. If you're playing open 5ths on a row (or the odd B-F tritone), it's often the most efficient fingering, and it lets you add/remove the 3rd of the closed triad at will with a single finger. I use this all the time.

[R Small]

Thanks MTGuru. That sets my mind at ease. I don't want to pick up any bad habits. By the way, the particular chord I was wondering about is from the Bach Cello Suites (violin transcription). In the giga (jig) of Suite 1, 4th measure, there's a chord starting on low D, then A, then F# with a trill to G. I play this by barring (I gues you could call it) D and A with R1, then F# with L3, then trill G with R3. It's a little tricky but possible.

[MTGuru]

the particular chord I was wondering about is from the Bach Cello Suites (violin transcription). In the giga (jig) of Suite 1, 4th measure, there's a chord starting on low D, then A, then F# with a trill to G. I play this by barring (I gues you could call it) D and A with R1, then F# with L3, then trill G with R3. It's a little tricky but possible.

That does seems like a reasonable solution. You could also try playing the D and A with R3 and R2, then grabbing the high G of the trill with R1. But I'd have to look at the score to see if that makes sense in context. And sometimes English concertina fingerings are like playing a game of Twister with your fingers. That's part of the fun.

[MTGuru]

I just looked at a violin transcription of the Gigue in D. And yes, I'd also grab the D-A double stop with R1, and the high G with R3. You can then use R2 for the E of the F# trill's ending mordent if you like, and finish with R2 for the A-E double stop. That's not too "twisty".

[R Small]

Yes that's exactly what I do. Probably the trickiest part is lifting R1 off of D while still holding A for the A/E double stop.