The single largest niche industry is based on Latin music. Latin music has long influenced American popular music, and was an especially crucial part of the development of jazz. Modern pop Latin styles include a wide array of genres imported from across Latin America, including Colombian cumbia, Puerto Rican reggaeton, and Mexican corrido. Latin popular music in the United States began with a wave of dance bands in the 1930s and 1950s. The most popular styles included the conga, rumba, and mambo. In the 1950s Perez Prado made the cha-cha-cha famous, and the rise of Afro-Cuban jazz opened many ears to the harmonic, melodic, and rhythmic possibilities of Latin music. The most famous American form of Latin music, however, is salsa. Salsa incorporates many styles and variations; the term can be used to describe most forms of popular Cuban-derived genres. Most specifically, however, "salsa" refers to a particular style that was developed by mid-1970s groups of New York City-area Cuban and Puerto Rican immigrants, and stylistic descendants like 1980s salsa romantica. Salsa rhythms are complicated, with several patterns played simultaneously. The clave rhythm forms the basis of salsa songs and is used by the performers as a common rhythmic ground for their own phrases.