Starting in the late 1960s in England, progressive rock, or prog rock, is an extremely diverse and creative sub-genre of rock. Bands aimed to stretch the boundaries of conventional genre traditions by employing compositional techniques and varied instrumentation more commonly found in classical, jazz, funk and folk styles. Important progenitors were The Beatles and the Beach Boys with their innovation in concept albums and unconventional instrumentation. 70s prog bands such as Yes, King Crimson and Genesis pioneered the use of synths and keyboards, now a distinctive characteristic of the progressive style. These bands also catapulted prog into the mainstream with hits like 21st Century Schizoid Man which fused jazz and hard rock influences, and Genesis infused catchy pop melodies with longer song structures and unconventional time signatures on records such as Selling England By The Pound.