Let us imagine a world in which the biggest rock stars of the 1980s somehow contrived to stay that way, preventing any new bands from challenging their hegemony. That means no Oasis, Stone Roses or Nirvana; instead T'Pau and Terence Trent D'Arby are still packing the stadiums, hard rock remains the domain of Poison and Motley Crue, and 12-year-old girls still scream at Bros, whose tattered 501s now bulge with middle-aged spread. If everything were that predictable, rock would cease to be a cultural force.

It sounds ridiculous, but that this is exactly what has happened to dance music. The genre's current fall from grace stems from the fact that it is dominated by the same DJs now as it was in 1988. Pete Tong, Danny Rampling, Carl Cox and Paul Oakenfold clearly realised they were on to a good thing - mixing two records together being right up there with wiring a plug in the difficulty stakes - and now display an attitude to retirement that would earn the admiration of an African dictator. Like elderly motorists, they just won't let youngsters overtake them.

So however depressing the tawdry, violent saga of the So Solid Crew became, it was difficult not to be cheered by the rise of their most famous members, the teenage duo Oxide and Neutrino. They radically revamped the UK garage sound, with a thrilling combination of rumbling basslines, spindly electronic tones and pop samples including, famously, the theme from Casualty. For their trouble, they were immediately blacklisted by a "committee" of middle-aged DJs with a vested interest in maintaining the musical status quo. Happily, their 2000 debut album, Execute, went platinum and spawned four hit singles.

Their second album indicates that Alex "Oxide" River may be Britain's most original dance producer. Most dance music chases its own tail, endlessly regurgitating tired breakbeats and disco samples. It attempts to charm with familiarity. River, however, takes risks, drawing in audiences with innovation. 2 Stepz Ahead sounds unlike anything else. Rap Dis abandons standard beats in favour of disjointed bursts of rhythm, punctuated by lengthy silences. Return of the Supa is a confusing and unique splurge of sound, squelching synthesised noise barely in time with a thunderous hip-hop beat. Supa Sensi offers rattling drums, dramatic orchestral stabs and whining industrial noise.

If 2 Stepz Ahead is a difficult album to listen to, it isn't because of River's jarring, experimental production, but because of rapper Mark "Neutrino" Oseitutu. His partner may be forging ahead, but Oseitutu remains stuck in a rut, harping on topics already done to death on So Solid Crew's debut album, They Don't Know. Self-pitying whining about envious "haters" is matched by leering descriptions of So Solid's wealth and fame: the subject of Oseitutu's Porsche comes up so often, you begin to suspect product placement. An obsession with violence and guns rubs shoulders with complaints about police harassment. It would be funny if it weren't so evidently devoid of irony.

Hip-hop has always thrived on braggadocio and threats. The tradition of the MC "battle" stretches from rap's 1970s roots to Eminem. But the point is less the insult than the humour and intelligence of its delivery. When rapper Xzibit calls producer Jermaine Dupri "a cock-eyed midget with a Napoleon complex", it's hardly subtle satire. Yet it sounds like the work of Peter Cook when compared with Oseitutu's efforts: "Your IQ must be about three", "You're like Mr Blobby", "You're fucking pricks." This is less lyrical battling than the witless hectoring of the playground bully. It's Gripper Stebson goes clubbing.

But Oseitutu's way with a withering bon mot is nothing compared with the charm he displays when dealing with the fairer sex. "I don't know her name, but let's call her a slapper," suggests current single Dem Girlz. Rap Dis II outlines his delectable seduction technique. "Bitch wants to fuck 'cause I'm famous, see, after I'm done can't chill with me," he cries. "Get the fuck out, no lift from me, no cab fare, not even bus money."

So Solid Crew apologists like to claim that anyone offended by their lyrics is too middle-class, old or white to appreciate that they are simply reflecting reality. But there is nothing illuminating about 2 Stepz Ahead's misogyny. That has nothing to do with race, class or age: it's just a bloke being vile about women in the hope that morons will laugh.

This illustrates the staggering disparity at the heart of 2 Stepz Ahead. The musical content sets its sights high, hurtling off into uncharted territory with a thrilling disrespect for the conventions and traditions that are smothering dance music. The words set their sights so low, they render a groundbreaking album virtually unlistenable.