In Cape Breton (don't know about elsewhere), it's played with two more parts, and with at least one double 'cut' - i.e., 'birl' - which is a tricky little trick; the best of them (meaning, Buddy MacMaster) can play a double cut as one steady machinegun-fire repetition of the note, but most play two more or less distinct triplets. (FYI!).
I might have mentioned as well that the 'double cut' (in the Cape Breton sense) requires the ability to start a cut (the second one, in this instance) on the up-bow .... @@TheFiddleChannel
