Trip-
OK, First keep in mind that today we are in a period where there is a trend toward standardization of the C/G three row anglo-chromatic concertina as the “normal” concertina for Irish music.
So if you want to take the “road more travelled” – at least among the crowds of folks who want to play Irish traditional music on the concertina
– get one of those and you will have many options to learn from books, workshops, and by conferring with other beginners. But since you asked about the D/A, it does in fact have some unique and nice features for the right student.
The C/G three-row (in most common 30 key versions) will have only the notes of the C scale (white keys of a piano) on the middle row. The inside row (nearer the handrails) will typically have only the notes of a G major scale (white keys of a piano except one – there are no F naturals; instead of those, the F sharps, which are black key on the piano, are present). 20 key (two-row) C/G concertinas will usually have all those same notes, (those 8 of the 12 notes of a piano keyboard, with F# the only black key). But on the typical three row C/G concertina, the outside row (away from the handrails) will have the final 4 notes of a piano keyboard (C#, Eb, G#, and Bb) in a few octaves, plus some extra low (E, F, A) and reverse-direction (G, A sometimes high D) and high (sometimes F, A) notes. You can easily find examples of the “Wheatstone/Lachenal” or “Jeffries” 30-button C/G anglo concertina button-note layouts online. THese are the two most common and are actually very similar.
For the experts, you already know there are many exceptions to the layouts I describe above.
The standard D/A concertinas in two or three rows have the same layout as a C/G, but transposed up one full step.
Your comments about the Morse concertina are a little confusing. The middle row of a standard three-row anglo is always named first when describing the keys; it is the lowest in pitch with the inside row pitched a fifth higher. So on a three-row C/G, the C row is middle and lower; on a three-row D/A, the D row is middle and lower; on a three-row G/D, the G row is middle and lower. Usually the G/D is pitched lowest of these key systems: the D row of a typical G/D concertina is in pitch with the D row of a typical D/A concertina, but the G row on the typical G/D concertina is an octave below the G row of a typical C/G concertina. All those “typicals” were inserted because there are also baritone concertinas pitched an octave below standard, and piccolo concertinas pitched an octave above standard.
You can learn to play Irish music on a C/G or a D/A and you can start on a two-row rather than a three row instrument in either key. For that matter you can learn on a concertina in any key or even on a one-row concertina (yes, some have been made). Later you might want to change for a different key or an instrument with more buttons – or maybe not. You almost certainly will want to trade up to the best quality concertina you can afford if you get serious about the instrument.
But the nature of your experience as a learner will be different depending on what key instrument you play. There isn’t a right or wrong; it depends on you and your circumstances. If there is a good player or especially a good teacher near you your best bet would be to follow his or her advice.
Among the older generation of players there were many different styles played and some of those seem to be neglected by many of today’s beginners and hobbyists. But if you can meet and learn from the very best players, or even listen very carefully to their recordings if that is all you can get, even among today’s players you may find more pluralism about keys and settings than might be expected from reading the posts on internet sites.
Good luck and best wishes,
PG
Oh, to answer your question, I believe the late Mrs. Hayes recorded on a three-row C/G Lachenal. I don’t think she used the third row much if at all on her first recording (“A touch of Clare”). According to Peter Laban, earlier she had a G/D instrument and years ago she must have played German ones in who knows what keys. Maybe Peter can tell us that as well. Her style and most of her settings could be played on almost any 2- or 3-row german or anglo concertina, but my point is that many of the settings she recorded would actually be in “normal keys” if played on a D/A.