They say legendry lysergic prophet Timothy Leary used to dose the drinks at parties with LSD, but it might not have been necessary. By the tail end of the 1960s, something was already in the air (and water) marking a radical cultural shift; recreational drugs were just one part of the anti-establishment equation. By 1967, year of the Summer of Love, the counterculture made a valiant bid to supplant the dominant culture, and in retrospect a strong case can be made that the counter-culture won.
At the forefront of this battle, in Britain, were acts like Pink Floyd, fixtures of the nascent underground psychedelic scene. Granted, they were fixtures of the infamous UFO Club and the toast of no less than Paul McCartney (allegedly a recent convert to the powers of psychotropic drugs), but the band never claimed to be spokespersons for the revolution. They weren't leaders but fellow travelers-- at least until their epochal debut, The Piper at the Gates of Dawn.
Piper was recorded at Abbey Road at the same time the Beatles were there recording Sgt. Pepper's Lonely Hearts Club Band, but the results couldn't have been more at odds with one another. Where the Beatles exerted complete control over the tools of the studio, Pink Floyd used the studio to lose control. It didn't hurt that the band's primary songwriter and visionary Syd Barrett was on the verge of permanently losing control himself. Less than a year after the release of Piper, in 1967, Barrett was out of the band, one of the most prominent and tragic casualties of the rock era. Of course, while Barrett lived out the remainder of his life as one of the psychedelic age's walking wounded, Pink Floyd went on to much bigger (if not necessarily) better things. Their catalog remains an AOR goldmine, the gift that keeps on giving for the band's principals, who, all said and done, released relatively few records during their heyday, but who have benefited a thousand fold from their efforts.