The music industry is in the middle of an upheaval: physical sales of CDs are down, but musicians like Trent Rezner are seeing success by offering their music directly to the consumers. At the same time, the industry is taking notice of the success of peripheral-oriented games like Rock Band and Guitar Hero, games that allow consumers to play and sing along to their favorite songs using plastic musical instruments. It's big business. Guitar Hero is a billion-dollar franchise and Rock Band is selling in large numbers as well. With a new update released in recent days, Rock Band has become even more of an innovator, now offering the sale of music tracks directly from the game's menus.