speaking purely as a drummer - I find that when you can anticipate the next few notes - you have learnt enough to not embarrass yourself.

There is a syntax to many tunes and maybe I compartmentalise tunes into types (within my own frame of reference) and some are just "not for this instrument".

I always tell ceilidh newbies that while they are struggling with the letters and phonemes we old hands are thinking in words and sentences.

Does this help?