Subgenres of drum & bass include techstep, hardstep, jump-up, intelligent D&B/atmospheric D&B, liquid funk, sambass, drumfunk, neurofunk and ragga jungle. Subgenres of other styles include progressive breaks, booty bass, Goa trance, hard trance, hardstyle, minimal techno, gabber techno, breakcore, broken beat, trip hop, folktronica and glitch. Speed garage, breakstep, 2-step, bassline, grime, UK funky, future garage and the reggae-inspired dubstep are all subgenres of UK garage. During the early 20th century, ballroom dancing gained popularity among the working class who attended public dance halls. Dance music became enormously popular during the 1920s. Nightclubs were frequented by large numbers of people at which a form of jazz, which was characterized by fancy orchestras with strings instruments and complex arrangements, became the standard music at clubs. A particularly popular dance was the fox-trot. At the time this music was simply called jazz, although today people refer to it as "white jazz" or big band. "Genres": Swing music, Western swing  "Genres": Rock and roll  In 1952, the television show American Bandstand switched to a format where teenagers dance along as records are played. American Bandstand continued to be shown until 1989. Since the late 1950s Disc jockeys (commonly known as DJs) played recorded music at nightclubs. In 1960, Chubby Checker released his song "The Twist" setting off a dance craze. The late 1960s saw the rise of soul and R&B music which used lavish orchestral arrangements. "Other genres": Funk  "Genres": Disco, funk, R&B, hip hop  In 1970, the television show "Soul Train" premiered featuring famous soul artists who would play or lipsync their hits while the audience danced along. By the mid-1970s disco had become one of the main genres featured. In 1974, "Billboard" added a Disco Action chart of top hits to its other charts (see List of Billboard number one dance club play songs). Disco was characterized by the use of real orchestral instruments, such as strings, which had largely been abandoned during the 1950s because of rock music. In contrast to the 1920s, however, the use of live orchestras in night clubs was extremely rare due to its expense.