The notes per se in an Irish tune book don't even contain anything like sufficient information about pitch and duration. Let alone that the whole tune as notated does not contain anyinformation about rhythmic subtleties, variation or ornamentation. And this constant comparison with classical music interpretation is somewhat bogus, with respect. There is nothing like the scope in classical for putting your own mark on it in terms of variation in melody and rhythm and for adding ornamentation. Just like there is nothing like the scope in diddley music for going off half-cock with the music as there is in jazz. Half-way decent musicians will listen to a lot of other half-decent (or better than half-decent) who play this music, not try to start from scratch, or, at best, with vague notions, with a tune-book.