ZZ Top is an American rock band, sometimes referred to as "That Little Ol'' Band from Texas". Their style, which is rooted in blues-based boogie rock, has come to incorporate elements of arena, southern, and boogie rock. The band, from Houston Texas, formed in 1969. Musician Billy Gibbons and drummer Dan Mitchell, originally in a band called the Moving Sidewalks, got together with bassist Lanier Greig (soon replaced by Billy Ethridge), to form ZZ Top. In 1969, Ethridge and Mitchell were replaced by Dusty Hill and (the beardless) Frank Beard from the band American Blues. The band soon began developing a following in Texas. They were signed to London Records in 1970 and released several albums, beginning with their 1971 debut album, followed by their 1972 album Rio Grande Mud. In 1973, the band emerged into the mainstream with the album Tres Hombres, and their 1975 follow-up Fandango! expanded on their sound and sense of humor. By the mid-1970s, they were among the most popular touring acts in the United States and broke various concert attendance feats. After years of touring, the band went on a two-year break in 1977, which resulted in Gibbons and Hill growing chest-length beards.