Alas I still think in terms of quavers, semiquavers etc, and I'm not sure what the starting point is in this hierarchy (breve, semibreve?) for breaking notes down into quarter notes, eighth notes etc.Anyway, to keep it simple, I'll say it this way: the basic 4/4 rhythm is 1,2,3,4, 1,2,3,4, etc with 1 and 3 accented more than 2 and 4; and 1, for that matter, accented more than 3.
Reels and hornpipes typically fit two notes to each beat to produce 1-and 2-and 3-and 4-and, in which the ands get less emphasis than the numbers to which I have linked them by hyphen.
In reels, the numbers and their corresponding ands are of equal time value; the distinction between them is just one of emphasis or accent. In hornpipes there seems to be wide discretion, according to region, local custom, the origin of the tune etc about how each pair of notes is handled. This discretion ranges from reel-type distinction beetween the numbers and the ands, though more pronounced, through to giving the "number note" 50 per cent more time, and the "and note" 50 per cent less.
It is the latter extreme that I am accustomed to for hornpipes in Ireland. It means each pair of notes is played (in my language) as "dotted-quaver, semi-quaver". Sometimes the musical notation actually expresses it this way; sometimes the notes are just written as straight quavers.
A triplet is three notes of equal length fitted into the time that would normally be allocated to just two of those notes. The notation is a phrase-curve linking the three notes, with a figure 3 over or under it.
In hornpipes, many a crotchet beat that would normally be given to two quavers is instead taken up with a triplet, which is expressed as three semi-quavers and notated as described above.
Reels should go at a faster lick than hornpipes, and strathspeys are broadly the same as hornpipes but with the emphasis reversed between the "number note" and the "and note."
And now perhaps I should apologise to anyone who is still awake. For my part I seem to have fallen asleep some time ago.......