Psychedelic music is a genre deeply influenced by the 1960s subculture that used psychedelic drugs like LSD, aiming to replicate or enhance altered states of consciousness. Emerging from folk and rock bands in the United States and the United Kingdom, it gave rise to subgenres such as psychedelic rock, acid rock, and psychedelic pop before its initial decline in the early 1970s, though it significantly inspired later movements like progressive rock and heavy metal.

Musically, it's defined by characteristics like Eastern instrumentation (sitar, tabla), disjunctive song structures, surreal lyrics, and extended instrumental segments. To mimic drug-induced effects like "dechronicization" and "depersonalization," artists utilize elaborate studio techniques such as backwards tapes, phasing, and early electronic instruments like the Mellotron or synthesizers. The 1960s "original psychedelic era" was shaped by figures like Timothy Leary, who advocated for consciousness expansion, and events like Ken Kesey's Merry Pranksters' "Acid Tests" in San Francisco. These legendary gatherings, often featuring LSD supplied by Owsley Stanley and music from the Grateful Dead, were pivotal in popularizing the psychedelic lifestyle.