Papa Roach and Black Eyed Peas once wrote a nu metal song together, and we have the proof

Ah, the early 2000s. What a delightfully exciting and straight-up batshit era to be a metal fan in. It was a time when heavy music was permeating just about every single strand of popular culture, be it conquering the charts, dominating movie soundtracks or taking over Wrestlemanias. It was a chapter in history during which you might see Slipknot rock up on Friday night UK telly, or Fred Durst and Christina Aguilera bust out a duet.

It was also a time where you'd get a collaboration between Papa Roach and The Black Eyed Peas.

Yup, really.

In 2003, following two albums that had seen them become something of a talking point in hip hop and r'n'b circles, The Black Eyed Peas underwent a transformation that'd see them become one of the New Millennium's single biggest pop acts. Bringing in charismatic vocalist Fergie to make the three-piece a quartet, the band released chart-topping single Where Is The Love?, unleashed a double-platinum album in Elephunk and took over the world.

Elephunk was anchored by four hit singles - Where Is The Love?, Let's Get It Started, Hey Mama and Shut Up - but it was the penultimate track on the album that offered what is still arguably the band's most unique collaboration ever. Teaming up with breakout nu metal stars Papa Roach, The Black Eyed Peas wrote Anxiety, an angsty, guitar-driven track at odds with most of the slick pop, rap and r'n'b hooks on the rest of the record (though Will.I.Am's penchant for obscenely bad lyrics remain - "Anxieties bash my mind in / Terrorizing my soul like Bin Laden") .

The collab was never released as a single and so didn't create many waves in its own right. There was, however, one performance of the song - in 2003, on an episode of short-lived live music show Pepsi Smash on The WB.

The performance is certainly animated, with all members of both bands swamping the stage, throwing a ton of shapes and, in the case of Papa Roach frontman Jacoby Shaddix, wailing into a megaphone. To date, the song remains Black Eyed Peas' only foray into nu metal. We suspect it may be the last.

Watch the lively performance below.