I use ABC notation all the time. It's a great way to store a lot of music scores and pass them on as they use very little memory, it all being just writing. There are a lot of freely available software options depending on your operating system. I used to use ABC2Win but when we upgraded to Windows XP it wouldn't work properly so I use ABC Navigator instead. Only downside of that one is that it doesn't include a beginners guide to writing ABC. For the uninitiated the ABC above for Little Liza Jane - you would highlight it, and copy the whole thing into an ABC file on your computer, then using your ABC program when you open it it transforms it into a nicely laid out score. The program will even play it back to you, including endless repeats and at whatever speed you want, which is great for learning new tunes. ABC Navigator uses a quite pleasant concertina-like sound.
On the whole I find it very easy to use and after a bit of practice to write tunes out in. So much so that if I was jotting a tune down in a notebook now I'd do it in ABC, then when I got home I'd type it into the program and it'd play it for me.
Brilliant. One downside is that it only works for a single melody line. So great for folk music, but not if you want a score that includes a harmony line. Another is that ABC written on one program might not be entirely compatible with another, so if you've downloaded a song, you might have to change it a bit to work on your program. Looking at Liza above, I can see in fact that it wouldn't play properly on ABC navigator - it wouldn't like the unfinished bars at the end of line one and 3. Easy to fix though.
Just do a search for ABC notation and you'll find useful `how to' guides.
I want to hear what pleasant concertina sound is.