The Numero Group’s ‘Wayfaring Strangers’ series seeks to catalogue curios from the annals of popular musical history. Following entries including a record of post-Sabbath rock that also spawned a Dungeons & Dragons-style board game, their latest collection shines a light on what happened when the hippie dream died and the acid turned bad. Acid Nightmares contains 18 hair-raising acid-/psych-/hard-rock numbers, all of which lean heavy on the fuzz. Highlights include every song with a mention of drug in the title (and there are a few of them) and Sunn Cycle’s ‘Acid Raga’, a curious dreamscape that closes the record. As well as being a generally enjoyable bit of over-the-top fun, Acid Nightmares also provides the missing link between hippie-rock and early metal.