Thank you McGrath of Harlow. I consider that high praise. Yes, people have been very kind and friendly to me since I joined the Mudcat.
Jon Freeman, when I read your response, I thought that it sounded very logical, and it does sound logical. After thinking about it for a while, though, I find that I now have more questions than I did before.
For instance, an opera has lyrics and a melody, but I don't think it would be considered a song.
On the other hand, the pieces of music that I listed on the song thread are much more than melodies or tunes. They are musical compositions with several parts, each of which could stand on it's own. When I play them with chords on my accordion, they have complex rhythms and textures. However, they are not particularly long, so the word "composition" seems a little too large for them.
I'm still mulling it over, but I think I would be interested in hearing what Malcolm Douglas has to say about this. (You there Malcolm?)