American pop is a vague and nebulous term, applied generally to whatever form of music is most popular among mainstream Americanteenage audiences. Adolescents are an especially important audience, both because of their relatively large amount of discretionary spending, and their fervent devotion to pop stars. Though the modern era of teen pop music is not usually said to have begun until the 1960s, there were important antecedents.
Perhaps the first genre of teen pop was the swing craze, which was an important dance style among teens across the nation in the early part of the 20th century. Later, a number of vocalists like Ella Fitzgerald and the Ink Spots became very popular, especially among the young. Though these performers are not generally considered teen pop singers, their success indicated that music that appealed to teens could be highly profitable. A number of Italian-American crooners soon found a major youth audience, including Dean Martin, Rudy Vallee, Tony Bennett, Perry Como, Frankie Laine and, most famously, the "first pop vocalist to engender hysteria among his fans" Frank Sinatra.