Thaius said:
I'm pretty sure that a song is simply a piece of music, with or without words. I mean what else would we call instrumental music? A piece? A music? I've never heard that distinction of the word, and my father's a music teacher. I'll have to look that up I guess...
it's just a tune usually.
it might have other names depending on it's purpose, but that's a pretty general name.
singing needs words. otherwise it isn't singing. if you hum some tune to yourself, it's not singing. if you play the flute (for example) you aren't singing.