Theres a lot of Irish muisc in D( a D accordion), but theres a lot in G (a C accordion) and A-minor (a C accordion). There's some differences in the tuning, as a Cajun is tuned with flat 3rd's and 5th's while Irish accordions are equal temperment tuned. Its worth looking up what these tunings are on the internet.
Listen to Johnny Connolly (from Ireland) play a one row for Irish muisc. I think he got one from Jr Martin, but it was re-tuned to equal temperment tuning. He's one of the best on Irish one rows.
I have played Irish muisc for a long time on pipes and whistles but love Cajun muisc and recently got an excellent D Cajun accordion. I did not find Irish muisc easy to play on a one row. Perhaps I'm trying cover too many types of music and concluded that if I want to play Irish music I'll play the uilleann pipes. If I play Cajun, I'll get the Cajun accordion out.
But if you want a one row to play Irish music, for me it would be the D accordion.
I used to play Irish accordion, a beautiful Cairdin Mini Deluxe, and almost everything I played was in D & G. I would go with the D if you were hoping to play Irish on a Cajun box.
Of course, I havent picked up my Cairdin since I got my Larry Miller box in August!
C# D is very often used for two rows. Trad players like Charlie Piggot play the ëxtended one row, wich means D and the half notes on the other row. A lot of stuff can be played on the one row. D is preferable. Listen to Tom Dogherty from Donegal/New York, a one row player from the past. PLays one row, guess in D.
That the tuning for the elbow pipe is D is not quite correct. In the past they were also C, Bb and maybe more. But D is called the "concert pitch" as I am well informed. So nearly everybody plays D.
Tha't what I understood. But the Irish will know better, of course.
Last summer I went to Celtic Week at Swannanoa Gathering near Asheville NC.
In addition to workshops fpr uilleann pipes I took the Irish accordion worshops with noted Irish player, James Keane. Everyone there had two rows and I had my C accordion from Jr Martin. I learned alot just by watching the class.
However James Keane was delighted that I had a one row and after the class he played it for hours. Also told me this is what people in Ireland use to play before
they developed the Irish two row accordion.
My friends in Ireland say the one row accordion is making a come back and they do use it in many competitons.
Links above are on Johnny Connolly for those interested.
So go for it Danny and play the one row! Irish or Cajun, you'll love it.
It is an instrument that can stand on its own.... Ed
Gotta watch the tuning of a cajun box though. I think Cajun uses a lot more chords and blends than Irish, and the cajun box has a different tuning from other boxes.