There are quite a few in The Digital Tradition, a free 4000+ strong database (many with tunes to play on your computer's speaker). It is available to FTP from ftp.uwp.edu, or mail email@example.com for more information. There is also a lot of other musical info and folk info on that ftp site. Particularly watch out for the October 94 edition which should have a lot more Scottish material
Also, check out the Ceo\l section of the Gaelic Homepage.
To the Gaelic Homepage