ITUNES shifted the music business toward a singles-based model. While artists still release full albums, it’s also possible to produce a massive iTunes hit, like Carly Rae Jepsen’s “Call Me Maybe,” before an album is even available (Jepsen’s full album sold modestly upon its later release). But some artists can still sell full-album packages: Beyoncé’s self-titled album (including a series of music videos to accompany the music) was released exclusively to iTunes for its first few weeks and promptly broke sales records for the site. © Rick Davis/Splash News/Corbis