Most of my favorite guitar riffs are simple. The opening of EATB's Rescue. Or Trail of Dead's Relative Ways is a simple ditty. 2, 3, 4 notes sometimes y'a know? Bowie's Andy Warhol I think is a variation on a scale (F?). And Bowie in particular writes complicated chord patterns, and jazzy chords; but most of my favorites don't require that sort of musicianship.

Give us your thoughts on writing a catchy melody, either bass line or lead guitar riff. How to do it, what makes it good or bad. Robert Smith drinks a few bottles of red wine to get into it. What do DiSer musicians do when writing a song?