Emerging in the mid-to-late 1960s, psychedelic rock was spawned by the expanding hippie counterculture that originated on the West Coast of America. Bands such as the Grateful Dead, The Byrds, The Doors and Jefferson Airplane played pioneering loud, rock music that reflected psychedelic, drug-induced states. The Byrds were particularly influential, with their implementation of electric instruments in the mid-60s. Around the same time in Europe, similar ideas were being explored, especially in the now landmark album, Sgt. Pepper’s Lonely Hearts Club Band by The Beatles. The Yardbirds, and especially Jeff Beck, were instrumental in popularising psychedelic elements in rock music with hit singles such as Shapes of Things which demonstrates guitar work using a fuzz tone and ‘exotic’ sounding scales. Psychedelic rock is often recognisable by the use of inventive sound effects such as phasing, reverb, feedback, and wah-wah pedals. Non-traditional western rock instruments were also introduced — Indian instruments, the Mellotron and the organ. The lyrical themes of songs are often ambiguous or abstract and lengthy improvised guitar solos are regular features.