Why did pop musician Björk decide to record 2004's Medulla as an almost entirely vocal album? How does singer-songwriter Ani DiFranco use music to express her political views without evangelizing about them? These are the types of questions music writer Anil Prasad has asked since he launched online magazine Innerviews in 1994. Now a collection of 23 of his best interviews are available as Innerviews: Music Without Borders (Abstract Logix, $19.95).