For a while, I had been considering ranking Physical Graffiti #1 on this list. It’s my personal favorite these days, for all the reasons I just listed. When it comes down to it, though, Led Zeppelin’s untitled fourth album (often referred to as “Led Zeppelin IV” or “ZoSo,” amongst a bunch of other less common names) is one of those undeniable feats. After the artistic change-up of Led Zeppelin III garnered the band more critical dismissiveness, they returned with the album that would, in hindsight, function as the capstone to their legendary first four album run, and would effectively become the centerpiece of their catalog.

Where Physical Graffiti touched on all Zeppelin’s different sounds and interests by stretching out and holding all the permutations at once, the fourth album does something similar with remarkable sharpness and economy. There are eight songs here. There might not be genre workouts quite as overt as “Trampled Under Foot” or “The Crunge,” there might not be songs quite as spaced out as “In The Light” or “No Quarter,” and there isn’t anything that hints towards the synthesizers of In Through The Out Door or the loose progginess grazed by the band’s last two albums in general. But these eight songs still, in some way, seem to capture every element of the essence of Led Zeppelin. These eight songs are also, it should be mentioned, completely bulletproof.

On some level, it’s easy to get sick of the fourth Zeppelin album. When I’m talking about over-exposure of Zeppelin’s classic material, this is the key album. How many times have you seen someone wearing a T-shirt with the cover? How many times have you seen it, just hanging around on a shelf at Target or Best Buy, alongside Born In The U.S.A. and The Black Album and a few Beatles records? How many times has someone referenced the “No ‘Stairway To Heaven'” joke from Wayne’s World, and — if you’ve spent any time in guitar shops — how many times have you heard a young musician give it a shot in public anyway, alongside “Black Dog?” It’s one of those albums that’s so inescapable that it’s easy to write off; admit it’s a classic, move on, don’t listen to it for a decade.

For years, the only song I really went back to on the untitled record was “When The Levee Breaks,” one of the comparatively less over-exposed songs here. Also, this is another one of those perfect Zeppelin songs, and it still sounds insane over forty years later. That drumbeat, that way-out-there harmonica — it’s one of the most cinematic, enveloping song intros I’ve ever heard. It comes at the end of the record, but feels like a rupture, an opening into some journey beyond the experience the album’s already taken you through.

After putting the other songs away for a while, though, revisiting them has made them sound incredible all over again. Having gone through Zeppelin’s catalog for this, I was struck, in general, by how well most of it has aged, how exciting it still sounds, even with all the knowledge of how tired these sounds became in the hands of less competent or visionary artists. The fourth album is the linchpin to that. As an album, it’s simply perfect in the way of Rumours or Born To Run; there is an impeccable balance to its structure. Until pop culture fades entirely in some sort of, I don’t know, complete collapse of the internet and society or something, Zeppelin’s probably going to always be legendary. There are a lot of reasons for that, but the fourth album is the key one. This album, like only a few others out there, feels truly immortal.