I love this instruction from This Year You Write Your Novel by Walter Mosley.
Poets know that poems are songs, but few of us realize that novels are too. If there is no music to your novel, no sound, then the book will be at best incomplete. You must have a rhythm to your characters, a unique cadence to the way each one speaks, an identifiable cacophony to the world(s) they inhabit, and a beat to the story that, when varied, gives the read an almost unconscious sign of events about to unfurl.
No one will tell you how to score your novel, so that means you have to discover the music for yourself.