While there has always been "popular" music in the United States, and all forms of music are popular with certain audiences, the term "pop music" generally denotes forms of music that are non-classical, very mainstream, intended for very wide audiences, and often controlled by the giants of the music business: sheet music publishers in the early decades of the century, recording companies after 1930. While these companies often produced a great variety of music, their need for profits mandated a constant search for the "next big thing," the next great artist, or style of music whose popularity would generate big record sales. Thus fueled by the profit motive, companies sought to reach the widest markets possible. And while the large companies did produce music targeted at markets considered "marginal," such as the African-American population, they tended to focus on music that was unchallenging, unthreatening, and palatable across...