music. Another important change in music during the early 1960s was the American folk music revival which introduced Bob Dylan, Joan Baez, Pete Seeger, The Kingston Trio, Harry Belafonte, Odetta, Phil Ochs, and many other singer-songwriters to the public. Girl groups and female singers, such as the Shirelles, Betty Everett, Little Eva, the Dixie Cups, the Ronettes, Martha and the Vandellas and the Supremes dominated the charts in the early 1960s. This style consisted typically of light pop themes about teenage romance and lifestyles, backed by vocal harmonies and a strong rhythm. Most girl groups were African-American, but white girl groups and singers, such as Lesley Gore, the Angels, and the Shangri-Las also emerged during this period. Around the same time, record producer Phil Spector began producing girl groups and created a new kind of pop music production that came to be known as the Wall of Sound. This style emphasized higher budgets and more elaborate arrangements, and more melodramatic musical themes in place of a simple, light-hearted pop sound. Spector's innovations became integral to the growing sophistication of popular music from 1965 onward. Also during the early 1960s, surf rock emerged, a rock subgenre that was centered in Southern California and based on beach and surfing themes, in addition to the usual songs about teenage romance and innocent fun. The Beach Boys quickly became the premier surf rock band and almost completely and single-handedly overshadowed the many lesser-known artists in the subgenre. Surf rock reached its peak in 1963–1965 before gradually being overtaken by bands influenced by the British Invasion and the counterculture movement. The car song also emerged as a rock subgenre in the early 1960s, which focused on teenagers' fascination with car culture. The Beach Boys also dominated this subgenre, along with the duo Jan and Dean. Such notable songs include "Little Deuce Coupe", "409", and "Shut Down", all by the Beach Boys; Jan and Dean's "Little Old Lady from Pasadena" and "Drag City", Ronny and the Daytonas' "Little GTO", and many others. Like girl groups and surf rock, car songs also became overshadowed by the British Invasion and the counterculture movement. The early 1960s also saw the golden age of another rock subgenre, the teen tragedy song, which focused on lost teen romance caused by sudden death, mainly in traffic accidents. Such songs included Mark Dinning's "Teen Angel", Ray Peterson's "Tell Laura I Love Her", Jan