Donovan
Donovan was one of the first pop musicians to denounce the use of drugs, after his own arrest for hashish possession in 1966, and his seeing friends begin to use "hard drugs" like heroin and speed (amphetamine). The liner notes to his 1967 album A Gift From a Flower to a Garden called upon young people to "stop the use of all drugs, and heed the quest to seek the Sun." (He later resumed occasional marijuana use, and drinking alcohol.)