“What makes Apple’s new music distribution system so delicious (if not downright insidious) is that you don’t think of it as a music distribution system. Apple has managed to fashion a near-perfect retail outlet on the Web. Taking pages, obviously, from Amazon, and less obviously from Starbucks, Crate & Barrel and a few other vanguard retailers, Apple has drafted a new book on experiential marketing. The ease with which a music aficionado can browse and taste the surfeit of offerings subtly smoothes the path to purchase. And the onetime registration of the credit card (not to mention that 99