I have a small 35 button Crane or “Triumph” system duet. My box was made in 1935 for the Salvation Army and has the SA stamp on it. I bought it from Barelycorn Concertinas in England a few years ago.

I will be putting some recordings here of my 35 key. You can hear many concertina recordings in the links and recordings section

I play mostly Celtic and folk music with my concertina. Some of the Scottish songs benefit from playing drone notes to imitate the bagpipes.

When I go to play concertina I usually reach for my 35 button first, mainly because its sitting right there on the couch... Ok, in truth I just like it better than the bigger concertina - its a raucous box with a lot of spirit. My particular box has a bit of quirk: the upper most Eb has been substituted with an A. Its great if you like A minor, not so good if you like E maj.

I can play almost any melody in my collection on my 35 key box. I reach the limit on the upper octave precluding a lot of transposing other than downward. Still, I can play many tunes on my 35key.

35 buttons isn't a lot to work with when the system is uni-sonoric. Three chromatic octaves would be 37 notes but we have 3 notes of overlap so the 35key misses 3 octaves by 5 notes (so about 2.6 octaves). Most melodies fall within 1 or 2 octaves, so when it comes to melody 35keys is almost enough to play any melody in any key.

With so few overlap notes the 35 key Crane qualifies as a duet with no overlap. If you have ever wondered what a duet would be like with no overlap then try a 35 key box.

The double treble clef notation which is often found for guitar or mandolin duets can be almost be read directly (one part for each side). I came up with some elaborate clefs and currently I am undecided, but continue to use my treble clef melody notation whch is the bulk of my sheet music.

Playing an actual duet can be difficult. On my 35 key I focus on melody and occasional chords. I often use my duet to double notes, play “call” and “answer”, drone out bag pipe like notes, and sometimes just chords.

I have kind of settled in on my 35 key, though I may still someday acquire a bigger box, I have found that the 35key pretty much provides me all the concertina I need.