With new ads on MTV promoting their cell-phone ring tones in advance of their new album’s release, the band Green Day is a veritable case study of the blurring between music and marketing. Ring tones are huge business in the UK – a new major source of revenue for the music industry. And now US bands are following: rap stars 50 Cent and Snoop Dogg have recently signed ring tone deals. Consumers seem to want the tones, and U.S. record companies, looking to boost sales, are eager to oblige.