Brendan Breathnach

Brendán Breathnach was an Irish piper and a music collector. I first got interested in him after hearing another harper had found nice, simple tunes in his collections. I like the older sounding, slightly more stark Irish tunes and his collections sounded like a possible source. His collections are called Ceol Rince na hÉireann vols 1-5.

Wikipedia has a nice article:
http://en.wikipedia.org/wiki/Breand%C3%A1n_Breathnach

Also by TG4 -
http://www.youtube.com/watch?v=q9AG2AC7LdE

Someone doing some indexing work using Brendán's collections and interfacing it with an ABC search:
http://msikio.online.fr/Breathnach/bbcode.htm
A nice detail from the video link below is that Brendán included name and location of each tune in his index allowing him to build up a "map" of where each tune was played. I don't know if he ever publishing this as a map - I'd love to see it. Might work incredibly well as an online thing - you type in a tune name and the bits of the map flash green where that tune was known.

Long interesting biogrpahic article from the Journal of Music:
http://journalofmusic.com/article/301

JStor has links to another article:
http://www.jstor.org/pss/20522525