Acid rock and Rock 'n' roll

Acid rock noun - A musical style that emerged in the 1960s; rock music inspired by or related to drug-induced experience.

Rock 'n' roll and acid rock are semantically related. In some cases you can use "Rock 'n' roll" instead a noun phrase "Acid rock".

Rock 'n' roll noun - A genre of popular music originating in the 1950s; a blend of black rhythm-and-blues with white country-and-western.

Acid rock and rock 'n' roll are semantically related. Sometimes you can replace phrase "Acid rock" with "Rock 'n' roll", this phrases are similar.