Hi, Naemanson - you pose a good question There are lots of tunes available, both in the database and on our Mudcat Midi Page, which you can reach through the "Quick Links" dropdown menu on most Mudcat pages. If a song in the database has a tune, you'll find it through a "click to play" link at the bottom of the lyrics.
It's an area where we're lacking, though. We need volunteers and ideas, so we can add as many tunes to the datyabase as we can. Some of us don't have the musical ability to transcribe a tune into notation "by ear." Others don't have the technical ability to use MIDI or ABC. I lean on Alison and Blessings Barbara to transcribe from recordings at times, but I hate to impose on them too much and it would be nice to have some other "by ear" transcription volunteers. John in Brisbane has done an outstanding job of adding tunes to the database, but we need more.
In the meantime, one thing you can do is ask somebody to go on HearMe and sing the song to you.
-Joe Offer-