The Beatles transformation from pop superstars to psychedelic rockers was influential not just in music but in society. What was one prime instigator for this evolution? Acid! George and John were unknowingly dosed by a shady dentist in 1965 and it changed their life. Later that year they dosed again at Zsa Zsa Gabor’s Los Angeles mansion. Ringo and some other celebrities joined them this time and they had an intense trip. This party also included their first exposure to Ravi Shankar and the sitar–an influence that would grow to gigantic proportions in later years. Vice recounts when the Beatles changed forever.