Led Zeppelin, if you take in the full measure of their annihilating sunburst grandeur, are a very hard band to categorize. They’re usually thought of as the gods of metal, and few would deny that — though it’s my opinion that the DNA of classic metal owes as much to Black Sabbath’s second album, “Paranoid,” as it does to Zeppelin. That said, Led Zeppelin loomed like figures on Olympus over the entire cosmos of metal: the hard-charging thunder chords and blistering guitar solos, the long-haired priapic strutting, the vocals that scream out their omnipotence, the eroticized vandalism, the power.

Yet I also think of Zeppelin as the Beatles of heavy metal. There was a yin to their destructive yang — the songs they would do, like “Going to California” or “Thank You,” that conjured a vision of life as incandescent and romantic and glorious. The place where the hippie spirit still lived in them.