I may have the beginning of some answers to this one. It also related to a question I asked in the Software forum under the topic "Using abc with Wordpress" so I'd like to repeat part of that question here. What I have found is that there are various sites that allow users to post tunes in abc notation. An easy one to join and get into is The Session, https://thesession.org/
. Although focused on Irish music it is by no means limited to Irish tunes. Others you might try are Folk Tune Finder http://www.folktunefinder.com/
and the Traditional Tune Archive http://tunearch.org/
. There's also some discussion of the Traditional Tune Archive on The Session, here: https://thesession.org/discussions/28674
. One to try for English tunes (and Cornish?) might be Folkopedia http://folkopedia.efdss.org/
- but that one seems to have no good facility for posting tunes in abc notation. The tune I was researching just had links to sound files and abc files hosted elsewhere, and that may be the norm for this site. Perhaps the EFDSS is nervous about copyrights.
This brings me back to one of the questions I asked in under my "Wordpress" question, which is - what's the best site for hosting a personal tunebook to make it available publicly? The answer might be among the sites I have already mentioned, but I'd like to hear from others who have experience of doing this.