As the ‘60s counterculture expanded beyond early epicenters like the corner of Haight and Ashbury in San Francisco and the UFO Club in London to become a mass youth movement, its influence on the era’s music became more pervasive. Everyone from music’s biggest stars to the underground’s most adventurous acts sought to expand sonic frontiers in the same way that marijuana and LSD expanded their impressionable minds. The Beatles led the way by reinventing the studio as a playground, experimenting with new multitrack technology to create the hallucinatory likes of “Tomorrow Never Knows.” Young guitar heroes like Jimi Hendrix and the Grateful Dead’s Jerry Garcia drew inspiration from free jazz and raga to create captivating spirals of sound. Even the bubblegum pop of The Lemon Pipers took a trippy direction thanks to wah-wah pedals, phasing tricks, and other effects that continue to trigger the best kinds of flashbacks.