acid rock
noun /ˌæsɪd ˈrɒk/
/ˌæsɪd ˈrɑːk/
[uncountable]- a type of rock music that was popular in the 1960s when many groups and their audiences used acid (= a slang name for the drug LSD). US groups such as the Grateful Dead and Jefferson Airplane were typical of this style. Their mysterious songs, played on electronic guitars, were much influenced by drugs.