By "melody" I mean that it has to consist of clearly deliberately arranged tones. By conventional definitions, it's true that a lot of what Bach and Glass do isn't melodic, and a lot of what I listen to is even less "melodic" than they are. I specifically referred to "the human voice in tonal manners" to differentiate a cappella music from spoken-word performances, but my diction probably wasn't terribly precise.

Basically, what you said about "organised sound" is about right.