John Chambers site (see above) also has the following, which looks as if it may be useful - point it to an abc file and it will play as a MIDI file on your PC. But I haven't had a chance to try it.

Quote from the site:
suppose you have an ABC file on your own machine which is running a web server, and you'd like to convert it to MIDI. Here is a URL that you could type into your browser's URL entry widget that will do the job:

http://trillian.mit.edu/~jc/cgi/abc/TuneGet?F=MIDI&X=0&U=http://localhost/some/dir/foo.abc