Valmai, thanks for some helpful and interesting insights. Oddly enough, I personally think the S of M "sings" more in A on the mandolin and fiddle. It utilises the lower strings on the mandolin in D, and can sound slightly muddy as a consequence. Playing it in A uses mainly the 1st and 2nd strings - and gets one up beautifully to the 10th fret - wheee.

Tenor guitarists cheat, of course. They use a capo on the 2nd fret and play in G!