G'day Rick,

What John J is essentially correct - two-row accordions can be just 2 one-rowers squeezed together, but there are variations:

The Irish (and other European groups) style two-row is chromatic - with two rows set a semitone apart ... B/C, C/C#, D/D#. The classic old Hohners were Double Ray models.

The 'standard' two-row has an inner row a fourth above the outer one - D/G is the 'standard British melodeon', G/C is common here in Australia (I had to persuade the Hohner concessionaires to import me a batch of the English D/G specials when they ran a batch at Trossingen). A/D seems to have a lot of Scottish adherents and C/F was common here between the wars - when old bush (country) fiddlers preferred to keep their fiddles pitched a tone low to reduce the strain in hot weather, so they fiddled like in D and G today but the pitch was C and F.

Another difference is whether the lowest notes are part of the chord series - like on a mouth organ. The commonly imported Hohner models here have those keys tuned as semitones from the middle scale. I was told by the retired importer that this was because Australia always got an offload of the models bound for Argentina ... for tangoists ... and they needed the semitones.

I ended up with a three-row (C/C/F) with the straight-through (no semitones) tuning - and sort of explored it and the advantages of having 2 more melody notes per row ... then found I had got used to the semitone tuning and had these reeds retuned, so I only have to think about one arrangement.

Keep at it - look at all the cultures that have made virtues out of what button accordions lack! (Including the Cajuns, who play a repertoire inherited from chromatic fiddles on one-row melodeons.)

Regards,

Bob Bolton