Music – lead sheets for Public Domain Music
Turlough O'Carolan Tunes - The complete set of all known tunes attributed to Turlough O'Carolan.
Dulcimer Tunes - The Kitchen Musican has long been a standard collection of great tunes for the dulimcer.
O'Neill's Music of Ireland - the definitive collection of Irish music.
Allan's Irish Fiddler Collection - This will get you through most of most Irish jam sessions.
The parent site is the Mudcat Café. That’s an eclectic gathering of folkies. One can spend hours reading through the discussion threads http://www.mudcat.org/threads.cfm
Irish and Scandinavian Tunes
This collection is written in ABC format. There are about 1,900 tunes in the collection. It’s free.
http://www.norbeck.nu/abc/ The official explanation of ABC format can be found at this site http://www.gre.ac.uk/~c.walshaw/abc/ “ABC is a language designed to notate tunes in an ASCII format. It was designed primarily for folk and traditional tunes of Western European origin (such as English, Irish and Scottish) which can be written on one stave in standard classical notation”
Celtic Tunes
“Ceolas carries notation for several hundred traditional tunes, in various formats, along with music software and an index of most published tune sources and links to other sites with tunes and songs.”
http://www.ceolas.org/tunes/