Two years ago, Lou Reed & Metallica collaborated on a double-disc record titled Lulu, loosely based on plays written by German playwright Frank Wedekind. When the two artists announced the project earlier in 2011, the ingredients were enough to raise immediate jeers and memes from the internet hungry to take down something it didn’t understand.

What did these two acts, late into their careers, have to gain from something that sounded like a disaster? Nothing, but they did have a lot to lose, which is why even just two years removed, Lulu sounds like a timeless artifact that will inevitably be footnoted in the legacies of two decades-long careers from respected musicians. But it is undeniably a surprising, puzzling, and unique record, under-loved by the cultish fanbases of both acts and overlooked by everyone else.

Lou Reed had been pressing people’s buttons as early as 1975’s Metal Machine Music, a record created to please no one but himself. The four tracks of guitar feedback were just an early example of how audacious he could be, sometimes to great effect like with 1978’s Street Hassle, but other times not so much, like 2003’s The Raven, which brought in Hollywood actors alongside long-standing Reed collaborators for interpretations of Poe, which had a mix of music and spoken-word that marks the clearest precedent for Lulu.

Lulu is more than a meme, joke, goof, or some kind of troll from two storied acts. Reed’s solo career is long and contains many ups and downs, but even as he moved away from crowd-pleasers like “Satellite of Love” and into more experimental territory, he never made any music that wasn’t true to his vision. Lulu is uncompromising. You could name many bands that are hipper, heavier, somehow closer to Reed’s style than Metallica, but Lulu only works because Reed works with Metallica, and not Sunn O))) or Portishead. When you want punishing riffs, you want Metallica, and you also want James Hetfield’s immediately recognizable gruff, mannered yell. Whether or not you want to hear him scream the oft-quoted “I AM THE TABLE!” is another thing.

A common complaint against Lulu is that neither act complements the other, with Reed’s trembling, sometimes fragile voice clashing with classic Metallica thrash. “Junior Dad,” the record’s final and longest song, is the closest thing to an ideal blend of the two styles. But the point wasn’t to create something that neat; rather, the effort was in trying to meld two visions (three, if you count the source material) into a new experience.

Throughout his career, Reed was elusive in interviews, refusing to explain why he created the music he made, but I don’t think it goes any deeper than that he wanted to make tangible the ideas he had in his head. Lulu is a difficult, long, sometimes purposefully uncomfortable listen, but it is nothing less than the purest form of the project Lou Reed and Metallica set out to make. Reed was not kidding anyone when he said Metallica pushed him to be the best he’s ever been. You didn’t have to like Lulu, but to insist neither artist were making the art they wanted to make seems rude, inconsiderate, and lacking in something that’s gone missing: empathy. Why would they say something they don’t feel?

While the critical response was predictably dire, a few outlets gave it a fair shake. The Wire rated it the ninth best record of 2011, noting, “Lulu functions as the ultimate realisation of Reed’s aesthetic of Metal Machine Music.” Lulu was merely the highest-profile record of Reed’s extensive experimental work post-his 1970s halcyon days. It’s not the face-plant of Metallica’s St. Anger because it is not a Metallica album designed for punching walls, nor is it a featherweight record designed to blend in at cafes where people gather to discuss how important and valuable Reed is to a hip, elitist, high-art culture. Rather, it is a pure document of two giants challenging their fans by making music they felt an absolute need to create. There is no better dedication to make to a beloved artist, than to really hear what they were saying through their music.