Songs don’t take up any physical space, but musicians and their producers have to make a lot of choices about scale, like the number of instruments used and even the size of the studio. Los Angeles-based musician Mark Stewart records under the name Stew. He writes elegant pop songs and good old-fashioned rock. He and his writing partner Heidi Rodewald talked to us about making those choices between simple and complex. Produced by Jocelyn Gonzales.