Hi - l'm a former fiddler who switched to viola a number of years ago. I still love playing fiddle tunes, so I ended transcribing and transposing into alto clef (and usually down an octave) a lot of tunes. I've put them into a free collection. There are 450+ tunes, mostly from New England. There are two formats -- large, with (usually) 1 to 3 tunes per page; and small, with more like 4 to 6 tunes per page. The collection is available in PDF. I did the transcribing/transposing in LilyPond, not ABC. The collection is available as PDFs or a zip file from my Google Drive folder <drive.google.com/open?id=1euNC...1h31_bBaQ> or, if you're not comfortable with Google Drive, from me as email attachment (zip only, the PDFs are too large for my email client). Just email me at <email@example.com>. All the best, Ralph P.S., I thought I had already posted something to this site, but I can't find it. . . .