The mash-up genre had been around for quite a while before Danger Mouse put out The Grey Album in 2004, but it's arguably the album to put the style on the map. He took the notion of blending two completely different bands and made it last for an entire album's length, and though a lot of its popularity stemmed from the controversy with EMI entertainment, it was an incredibly well done, as Danger Mouse himself put it, "art project." The same idea is present with the relatively unknown Wait What, who had his own great idea in combining the xx's invitingly dark yet dreamy debut, with the hard hitting, streetwise raps of the Notorious B.I.G.

It's a tad surprising how well equipped some of the xx's music is to be rapped over, something which is made evident immediately with Dead Wrong (Intro). Christopher Wallace's voice jumps right in as the drums kick up, and despite the hazy, melancholic beat it almost sounds uptempo. Basic Hypnosis blends the quirky percussion and hook of Basic Space with the confident, carefree flow of Hypnotize for an odd yet perky listen, which again, despite the melancholic backdrop almost sounds fun. There are of course, some downright harrowing moments on The Notorious xx as well. Suicidal Fantasy brings some of Wallace's darkest and most personal rhymes to the forefront, while Everyday Shelter sharpens his story of frustration with a life of dealing, both accomplished by pairing him with a wavering guitar hook and scant keyboards.

The biggest downfall of the Notorious xx is, unsurprisingly, that it's a typical mash-up album armed with little more than an inspired idea. Where Danger Mouse's Grey Album was loaded with different ideas on how to manipulate the Beatles' songs into beats, here the beats follow a simple formula on each track that gets repetitive very quickly: intro, loop, maybe a chorus with a vocal, and end. On multiple listens, the songs still sound good, but they lose their replay value somewhat quickly. One of two moments where DJ Wait What really deviates from his blueprint is near the end of The Curious Incident of Big Poppa in the Nighttime, in which Romy Madley Croft's vocals are slightly chopped up. The other is in One More Chance for a Heart to Skip a Beat's chorus, which almost sounds like banter between Croft and Wallace. However, their trade-off simultaneously shows the technical zenith and conceptual nadir of the album, as it feels more (perhaps intentionally) funny than atmospheric; it's basically Croft responding to Smalls' ode to his penis in a fashion that may as well be "hmmm... well, he do got that good dick."

The xx and the Notorious B.I.G. do end up sounding far better matched than one might think, even to the point of seeming obvious before the fact. The intimate and atmospheric music of the group really underlines a lot of Wallace's more personal and sensitive lyrics, resulting in a truly beautiful and unique listen. DJ Wait What doesn't offer much more creativity past the initial idea, however, and while The Notorious xx is definitely worth hearing, even if only for novelty's sake, it doesn't hold up for very long.