Sleep is a stoner and doom metal band from San Jose, California, known for helping define the genre in the 1990s. Guitarist Matt Pike and bassist-vocalist Al Cisneros have been the core members throughout the band's history. Sleep first emerged in 1991 with their debut album Volume One, then gained wider recognition with Sleep's Holy Mountain in 1992. After lineup and label struggles, the band briefly split, and their monumental album Dopesmoker was released post-breakup. Both Holy Mountain and Dopesmoker are now considered classics of stoner and doom metal. Reuniting in 2009 with drummer Jason Roeder, Sleep continue to perform and returned with the acclaimed album The Sciences in 2018. Their heavy, hypnotic sound and influence remain vital in the metal scene.