The Dark Side of the Moon is a little like puberty: Feel how you want about it, but you’re gonna have to encounter it one way or another. Developed as a suite-like journey through the nature of human experience, the album not only set a new bar for rock music’s ambitions, but it also proved that suite-like journeys through the nature of human experience could actually make their way to the marketplace—a turn that helped reshape our understanding of what commercial music was and could be. If pop—even in the post-Beatles era—tended toward lightness and salability, Dark Side was dense and boldfaced; if pop was telescoped into bite sizes, Dark Side was shaped more like a novel or an opera, each track flowing into the next, bookended by that most nature-of-human-experience sounds, the heartbeat. Even compared to other rock albums of the time, Dark Side was a shift, forgoing the boozy extroversion of stuff like The Rolling Stones for something more interior, private, less fun but arguably more significant. In other words, if Led Zeppelin IV was something you could take out, Dark Side was strictly for going in. That the sound was even bigger and more dramatic than Zeppelin’s only bolstered the band’s philosophical point: What topography could be bigger and more dramatic than the human spirit? As much as the album marked a breakthrough, it was also part of a progression in which Floyd managed to join their shaggiest, most experimental phase (Atom Heart Mother, Meddle) with an emerging sense of clarity and critical edge, exploring big themes—greed (“Money”), madness (“Brain Damage,” “Eclipse”), war, and societal fraction (“Us and Them”)—with a concision that made the message easy to understand no matter how far out the music got. Drummer Nick Mason later noted that it was the first time they’d felt good enough about their lyrics—written this time entirely by Roger Waters—to print them on the album sleeve. For one of the most prominent albums in rock history, Dark Side is interestingly light on rocking. The cool jazz of Rick Wright’s electric piano, the well-documented collages of synthesizer and spoken word, the tactility of ambient music and dub—even when the band opened up and let it rip (say, “Any Colour You Like” or the ecstatic wail of “The Great Gig in the Sky”), the emphasis was more on texture and feel than the alchemy of musicians in a room. Yes, the album set a precedent for arty, post-psychedelic voyagers like OK Computer-era Radiohead and Tame Impala, but it also marked a moment when rock music fused fully with electronic sound, a hybrid still vibrant more than five decades on. The journey here was ancient, but the sound was from the future.