...I remember reading an interview with Johnny Connolly and he basicly said the trick was knowing the music really well so you could sort of play around the notes that your instrument didn't have; by that I took it he meant something along the lines of choosing notes that harmonically worked with the melody.
That's one possibility, and one should be careful that such "harmony" notes also blend with any chordal backup that may be present.
Another "play around", and often much "safer" is to just leave out the notes you can't play. If others are playing melody, those notes will still be heard, but the change in overall tone and loudness where the melodeon drops a note can give a really nice emphasis to the rhythm.
Those techniques are needed for joining with others, where you know what notes they're playing that you can't. Workarounds in solo work often involve changing the melody line to a greater or lesser extent. It may not be "what so-and-so plays", but it has resulted in some really beautiful versions.
Thinking of this reminded me to take out my LP of John J. Kimmel for a fresh listen. Mmm!
On a 1-row box in D, he shows yet another kind of workaround... he plays "Rights of Man" in Bm, rather than the current standard of Em, with octave shifts (I might guess to avoid going off the end of the keyboard) in a few places.
The reason that Irish and Quebecois players have prefered the D melodeon, for the past century, is that it is the only one capable of playing in the three fiddle keys of D, G and A.
With a certain amoung of "fudging", or "working around" as noted above. The thing about a 1-row in D is that it only takes a little fudging for both G and A, while a 1-row G box would have serious problems with most tunes in A -- and vice versa, -- and either would still need some fudging in the key of D. D is the best compromise when working with fiddles, and at least as good as G when working with flutes, whistles, or pipes in standard tuning.
The Irish and Quebecois seem to have taken different approaches to playing in more than one key. Half-step boxes seem to be the preferred Irish solution, while the French Canadians seem to favor 2- and 3-row fifth-tuned boxes, sometimes carrying more than one (like some anglo players I know
). I've seen Philippe Bruneau play all of 1-, 2-, and 3-row boxes in a single performance.
The real difference between the melodeon and the half-stepped boxes is that ... on the Melodeons you just plain don't have those accidentals.
[Bill, I hope that my ellipsis has retained your intended meaning. If not, please correct me.]
It occurs to me that this difference results in qualitatively
different solutions to non-central keys on the two instruments. On the half-step boxes, all the notes are there, and if you want to play them all, it becomes simply a technical
issue. On a 1-row, any workaround becomes a musical
issue. (Of course, one can
also do musical workarounds -- varying the melody -- on a half-step box. But that's an option
. On the 1-row it's a necessity