Zeppelin attained rock ‘n’ roll godhood in 1971 with their eternal “Stairway to Heaven.” By 1973, the faithful were gifted Houses of the Holy, one of the band’s most eclectic and enduring albums. Thunderous riff rock (“The Ocean”) roared out of speakers alongside hard funk oddities (“The Crunge”), roots-reggae sunniness (“D’yer Mak’er”), hauntingly hypnotic hooks (“Dancing Days”) and, perhaps, an epic power ballad even more beautiful than “Stairway” (“The Rain Song”). Equal parts playful and fantastical, Houses of the Holy is a Seventies rock must-have for any record collector.