Popular rock bands are popular precisely because they make music that the "masses" can get behind. But there's also been cases of popular rock bands going rogue and making classic "eff-you" music, more commonly known as drone rock. From the groundbreaking anti-music of the Beatles' "Revolution 9" to the chaotic breakdowns in Radiohead's "National Anthem" to entire eardrum-pummeling albums by metal acts like Liturgy, the ambient drone comes in so many forms, making it hard to define.

But, like porn for your ears, you know it when you hear it. And you've probably been hearing it a lot lately, thanks to No Age (who just released Collage Culture featuring essay readings over music), and Chromatics (whose Kill For Love ends with 14 minutes of planetarium music). So here are five of our favorite examples of rock's ambient-drone tradition by artists who've sold a ton of albums, yet are still quite popular these days. Whether or not it's listenable, well, you be the judge.

1. Pearl Jam, "Stupid Mop"

This 8-minute bit of musique concrete is grunge's "Revolution 9." The foreboding final track from Vitalogy features rampant cymbal crashes, looped reverb, and various mental patients' spoken ramblings that Eddie Vedder recorded off his television. Mood music for budding serial killers.

2. The Flaming Lips, "7 Skies H3" (a.k.a. the 24-hour song)

Much of this day-long song is beautiful and accessible -- but after listening for eight straight hours at the office, it all just starts sounding like ambient noise. Especially the part that is ambient noise.

3. Smashing Pumpkins, "Drown"

The first four minutes are trademark Pumpkins - hushed vocals, pleasantly buzzing guitar. Then, "Drown" unfurls into a 4-minute screech of shoegazey feedback. Billy Corgan knows that sometimes, you gotta turn the dials up to 11 and let the noise smother everything until you run out of tape/memory.

4. Nirvana, "Endless, Nameless"

The hidden song that closes out Nevermind is easily the most ferocious song on this list. Dave Grohl's thunderous percussion holds together Kurt Cobain's avalanche of wails and shrieking feedback, and right when the song threatens to crush you under its suffocating heft...in comes a clean interlude allowing you to catch your breath.

5. Spiritualized, "100 Bars"

A whispered count to 100 blanketed with six minutes of ethereal textures: what did you expect from a space rock band that formed from the ashes of garage droners Spacemen 3?