You can’t pin Modeselektor down, and that’s just the way the duo likes it. Though they hail from Germany’s capital city, they don’t fit into the Berlin School of electronic music and don’t descend from any overt Krautrock influences either. Producers Gernot Bronsert and Sebastian Szary have cheekily described their sound as “happy metal, hard rap, country-ambient, Russian crunk,” while eschewing anyone who would “tag us as being a certain style or school or scene or whatever.”

Despite not releasing their first proper album until 2005 (Hello Mom!), Bronsert and Szary joined forces in the early ‘90s, first operating under the bland moniker Fundamental Knowledge before switching to the more dynamic Modeselektor (a function on the Space Echo effects unit) in 1996. Signing their first remix contract in 1999, Modeselektor ultimately found a home with the BPitch Control label, where they would release their first two records. They scattered a few singles beginning in 2002—including the contrastingly glitchy yet smooth instrumental “In Loving Memory,” which would end up on their Hello Mom! debut—but their first record actually came via an EP by their Moderat collaboration with fellow Berliner Apparat (Sascha Ring).

After making some waves with the well-received, mostly instrumental Hello Mom!, Modeselektor returned with a far more fleshed-out (and similarly exclamatory) Happy Birthday! in 2007. Spanning nearly 70 minutes, Happy Birthday! is as expansive as it is eclectic. Hip hop elements are pushed to the fore during a number of tracks, while others teem with world music influences, and Modeselektor never veers completely away from its IDM bread-and-butter (though the duo themselves would likely balk at such a restrictive definition). By 2007, Thom Yorke had professed his love for Modeselektor, citing them as one of his favorite groups. Happy Birthday! reaches the heights that it does largely thanks to a vibrant mix of contributors, including one that features Yorke himself in all his emotive glory.

The spastic Radiohead frontman’s most notable contribution occurs deep in the album. Like much of the record, “The White Flash” pays particular attention to the song’s low end, establishing a crisp and deep propulsive beat with stuttering effects. The ethereal atmospherics—largely derived from Yorke’s manipulated voice—drift in and set a wistful and slightly haunting mood long before the lyrics kick in. Yorke sings a simple song that hinges on the refrain, “You have all the time in the world,” which is both comforting at face value and troubling when one considers the ultimate ephemeral quality of life. Yorke is on point throughout the song, and coupled with the glistening production from one of his favorite bands, “The White Flash” matches and may even transcend the best of Yorke’s solo work.

Other collaborations abound, and the featured guests add dynamism to Happy Birthday! that simply wasn’t present on Modeselektor’s debut. The most bombastic of these is “The Dark Side of the Sun,” featuring Berlin’s best hand puppet-based hip hop group, Puppetmastaz. Snarling rhymes and propulsive, banging beats create a raucous and occasionally vulgar sound that’s unique on this album. Meanwhile, Apparat lends a hand (effectively making it a Moderat track) as the Caribbean-born and Berlin-based reggae singer Paul St. Hilaire joins in on “Let Your Love Grow,” spouting nearly indecipherable English in a moody, beat-heavy track that oozes with a world music vibe. Elsewhere, Miami’s breakcore artist Otto von Schirach adds his talents to “Hyper Hyper,” as mechanized vocals repeatedly call for a bass drum, with Modeselektor amply obliging. And early on, Parisian hip hop group TTC raps in French on a glitched-out, buzzing “2000007.” Modeselektor pal Siriusmo contributes to “Déboutonner,” and Newcastle’s alternative rockers Mamïxo Park turn “(I Can’t Sleep) Without Music” into a mellow but effective closer.

The non-assisted tracks also shine. “Sucker Pin” is an aggressive, unyielding salvo, and “The First Rebirth” turns lighter before dropping into an infectious, tubular beat. “The Black Block” continues with Modeselektor’s glitchier leanings and then plummets into a dark abyss, while “Edgar” incorporates chimes and a slower pace to drift up to lighter air. And the opening and title track uses an electronic reggae ditty to get the head bobbing right from the start.

In the years after Happy Birthday!’s release, Bronsert and Szary formed their own record label, Monkeytown Records, which has since released albums by Omar Souleyman, Siriusmo and fellow German duo Mouse on Mars, among others. The label also dropped two Moderat albums, and Modeselektor’s 2011 effort (appropriately titled Monkeytown), which was a smoother, more low-key affair. The busy duo has curated three Modeselektion compilation albums, and a third Moderat record is due out later this year. At this point, almost everything they touch is worth listening to, but it’s difficult to confidently say that Modeselektor has ever put together a more eclectic and compelling album since blowing out the candles on Happy Birthday!