Billie is obviously the primary songwriter for GD, but does he compose the drum and bass parts too or do Mike and Tré write those? Or is it just like, Billie writes the lyrics, comes up with the melody, guitar, and drum parts then brings them to a session and they go from there? He must have an idea of the rhythm, tempo, sound, etc in his head when he's writing songs, right? The boys don't really talk a lot about the technical process when they're making music and it would be interesting to know more. They tend to talk more about the creative process than who's writing which instrument parts and whatnot.