Hello chaps - I'm new to this so have a lot to learn about messaging, as well as the concertina. I like Jim Lucas' posting, very consstructive. I play a 30-button c/g anglo. I've been goin to an evening class/workshop for a year or so. The other 50+ people all play standard orchestral instruments, or classical guitars. We do small-group work for half the time, and full-group the other half - sort of, half chamber music, half orchestra. Its taught me that Yes, you can play classical on an anglo. And its also taught me a huge amount about counting and listening to what the others are doing (much more important than in most band work); and to be far more sensitive to how loud to play (not just loud and louder as in dance stuff); and to look and listen to the shaping of phrases ( how and when to get louder, quieter, etc); and to play normal, and more staccato, and more legato; and I've found out where all the buttons are, and what they do.I've also learnt some limits.
First, not to be too ambitious. I stick to what's written: which means sticking to one-line of notes. Music composed for keyboards of any sort, requires each hand to play a full chromatic range independantly - and that might be possible on a duet, but not on an anglo. I guess I could try and work out a variant sort of accompaniment for the left hand, but I'm not up to it.
Second, to listen out for the feel of the music. Classical has usually been written not just as a nice set of notes, but with particular sets of instruments in mind. This makes a huge difference to how the stuff sounds - pianos are great on attack in notes, but you can't shape a note on one; wind is less good on attack, but great on shaping; strings are similar. What works on one, doesn't always work on another - so, to me, classic ragtime only ever works on piano because it needs that brilliance and attack. I think its more useful to look at woodwind and strings music -though quite a lot of woodwind music is written for instruments which are tuned in B-flat, so it's written in a way which makes no real sense for the rest of us. I also think that having all the parts played by concertinas, gets pretty tedious - simply because all music is enriched by having a mix of qualities in the sound.
So I'd say, go for it - but with a bunch of other musicians, playing whatever stuff you all like; and making sure that at lest one of you is already good enough to be a guide.
Oh - recorder music for 2, 3, or more parts is a pretty simple and accessible place to start.