Followers of techno, deep house or the more open-minded ends of the UK dance spectrum over the last few years will doubtless be familiar with Leipzig's Gunnar Wendel by now. Despite being insular and self-contained in the extreme his music, primarily released under the alias Kassem Mosse but also occasionally as Seltene Erden and Kareem Moser, has elevated him to something of a cross-scene hero. It's tempting to see the adopting of Wendel's music by everyone from techno heads and house connoisseurs to the likes of Joy Orbison and Instra:mental as exemplifying dance music's current cross-pollinated state of affairs rather well. After all, here's an artist who, despite producing music that fits comfortably into no easy bracket - neither of genre, nor tempo, nor texture - lands places as far and wide as Panoramabar residents' sets, Ben UFO's mix CD for London station Rinse FM and line-ups alongside everyone from Juan Atkins and Move D to Rustie and DJ Rashad. Not for nothing is he known to many as The Bosse.

Still, to see Wendel's current success as representative of anything wider than his own music proves more problematic than helpful. Instead, he's better seen as more an entity unto himself. From a distance he's more akin to Chicago's Jamal Moss or the UK's Actress - an inimitable and rather mysterious figure, who rarely gives interviews and whose music tends to prune his influences almost to the ground, before regrowing them from the root again. Like those two artists, his wide appeal springs from his versatility - in his back catalogue sits everything from sumptuous electro and deep house to sketches built from deconstructed house music and tape hiss (Seltene Erden's Northern Rae EP), from the peak-time techno rumbles of '578' to the near Perlon-esque minimal of 'Enoha'. It's typically delivered in muted greys and browns, and clogged with dirt, as if he's unearthed ancient machinery and coaxed it back to life with a blast from the mains.

Move closer still, and what might initially be construed as rather austere or unforgiving becomes playful, fluid and intuitive. While his studio work thus far has continued to be unpredictable and near-endlessly inventive, it's the live arena that really shows off the Mosse flexibility. I've seen him set up a single slow drum machine groove and simply tweak it, with minimal embellishment and odd glimmer of melody, for an hour (in front of a saucer-eyed and stumbling Friday night crowd at a Dalston club, no less, near-clearing the dancefloor in an instant before rebuilding it from scratch). More recently, at Berlin's CTM festival, his set was fast, hard and peak-time, all splattery acid lines and hi-hat alchemy. Live he's revealed as being far from the stereotype of a withheld studio technician, always in motion, grinning, reshaping his own music in real-time, playing with audience responses. His grooves - dry, pockmarked and half-rusted away, but sensuous and self-seeding in ways that betray the influence of luminaries like Ricardo Villalobos and Thomas Melchior - explode into life at high volume, and even more so when placed within an entire set of his own productions.

For that reason, it's long been tempting to suspect that Wendel's music makes more sense once you've seen him live. It needs to be given time and space to operate, and requires patience on the part of listeners and dancers - another quality which makes his success in the build/drop driven UK scene rather unusual, given its tendency towards explosive dynamics.

All this has been a rather long-winded preamble to the release of his grandest statement to date, a collaboration with friend and frequent co-conspirator Mix Mup, released on vinyl by London label Trilogy Tapes. We've been sorely overdue a Kassem Mosse album - partially because his music only ever arrives in tantalisingly short 12" missives, but also because the album length is the only format able to replicate the time and space he's allowed in the live arena. So MM/KM is hugely gratifying precisely because it sets both producers' music in a longform context. Its six tracks are left to fray into one another's space, resulting in a continuous 33 minutes broken only by the need to flip the record halfway through. With additional time comes the freedom to be playful, even humorous: tossing dessicated hunks of Nina Simone's voice around for seven-odd minutes of turbulent, rapidly degrading house on 'Birds Flying In The Sun Like U Know How', for example, or allowing a groove to suddenly drop out, mid-bar, startling listeners. 'Galagonmixdown' passes through a number of different forms over its three minute length, each seemingly unrelated to one another: quietly creaking static suddenly and dramatically assaulted by deafening, staccato blasts of dissonance, and finally a jabbing hi-hat-driven rhythm that just as quickly cuts out again.

So the overall impression here is of two producers unafraid to toy with their listeners, especially those used to house music whose beats land with near-metronomic precision. Wendel and Mix Mup are clearly highly skilled at taming the unpredictabilities and more turbulent tendencies of their equipment - much as the prevailing wisdom states that the use of analogue gear makes it easy to get a looser and more 'human' sound, it takes a dab hand to make tracks this abrasive so infectiously groovy. This is doubtless tightly controlled, very intentional music. Nonetheless, a great deal of the pleasure in listening to MM/KM is the impression they give - whether true or false - that the music itself is forever on the verge of slipping out of their grasp and moving of its own volition. The duo are poised as custodians of an archaic, characterful, grumpy creature that's perpetually just about to seize the reins back and run amok. On 'Lost In NPE2', for example, a vivisected junglist break flickers back and forth through its superstructure, repeatedly scrambling its attempts to set up a comfortable groove before pulling away into long blurts of sci-fi radio interference.

It's the album's remarkable centrepiece, however, that neatly encapsulates the entire experience. The clue's in the name: 'MM KM End To Funk' opens the LP's second side as a stiff and uptight thing, kickdrums talcum dry and accompanied by the ra-ta-tat of a typewriter, before a house beat drops abruptly in the wrong place, terminally interfering with its futile attempts to gather momentum. Across its eight minutes these two separate strands of percussion flirt with one another, shifting in and out of phase, as if Wendel and Mix Mup were each wielding their own drum machine against one another in some archaic battle to the death. Out of the melee slowly unfurl long rips of hot, pitchshifted synth, their ear-shredding harmonies repeatedly lurching ever-higher into the red, producing unexpectedly beautiful, very brief moments high above the turbulence beneath. And, of course, to spite the title (again as playful as everything else here), Mosse and Mix Mup's best efforts to put an end to the funk fall on deaf ears. After threatening to do so for its first four minutes, it finally resolves into a lovely, crisp march, stretching buoyantly forward to a close, and the album's still wilder second half.