The 25-year anniversary of hip hop - the musical genre born in New York, which marries the production techniques of scratching and sampling, to spoken word rapping - has passed largely without fanfare. This seems a shame. It not only overlooks the significance of this popular art form, it also misses the opportunity to mark a potentially important shift in the centre of gravity of the hip hop 'nation'.

Black music genres, including hip hop, which once picked up the mantle of protest dropped by the rockers, are themselves lost in a haze of bling bling materialism: the social realism of say Grandmaster Flash's 'The Message' (1982), or the radicalism of Public Enemy's 'Fight The Power' (1989), have been drowned out by the rise of the celebrity ghetto fabulous anti-hero, Jay Z, 50-Cent, DMX, Master P et al, for whom "life ain't nothing but bitches and money". So, if rock is an aesthetic dead end; US hip hop and R&B (soul with a hip hop attitude) bloated, and 'dance' music (house, rave, techno) long past its peak, where can we look for signs of creativity, relevance, and (dare I say it so soon after Derrida's death) meaning? We could do worse than look again at hip hop here in the UK. I've said it before, and fallen on my face, but I'm going to say it again: British hip hop is where popular music, as a politically relevant, powerful and original force, is being reborn.

I've been a music journalist for about fifteen years. In that time I have had occasion, indeed many occasions, to suggest that British hip hop might be on the brink of establishing itself as a viable musical force on the popular landscape.

Starting in the mid 1980s there was Derek B, a rapper with a brace of hitlets, and M/A/R/R/S employing hip hop production and cutting techniques in their hit 'Pump up the Volume'. Later there was Soul II Soul, not hip hop exactly, but fun and funky music with Jazzie B intoning over the top in his London accent, and (whisper it) even hits in America. The hip and happening days of Acid Jazz in the late 1980s saw the brief flourishing of 'jazz-rap', all (self) conscious lyrics and African headwraps, the marriage of 'live' jazz, DJ technique and rapped lyrics. Except at the time I knew, as everyone did, that the rapping was hopelessly derivative of American styles - British rappers still failed to find their own voice.

In 1995 a real saviour, a potential messiah, came along in the diminutive and stumbling guise of Tricky. Formerly of Massive Attack, gender-bending, paranoiac, Tricky came out of the Bristol-based scene which had already made great strides toward establishing an authentic, non-American voice for British Black music, combining reggae, hip hop and dance styles into a new form of chill-out, beat-heavy music which went, briefly, under the unfortunate name 'trip hop'. Tricky's debut album Maxinquaye suggested a powerful new direction for British spoken word and beat music - and all in a West Country accent! Music would never be the same again! Then Tricky vanished, well moved to New York, produced a series of unlistenable albums, and has barely been heard from since.

But just as I was about to resign myself to the fact that this country, with its fascinating version of dysfunctional multiculture, is voiced to the world by the bombastic pub anthems of Robbie Williams and Oasis, or the anodyne crooning of Craig David and Daniel Beddingfield, I heard a rumour: British hip hop was a new force to be reckoned with, and that two new records proved it. Exhibit one: Showtime by Dizzee Rascal, and exhibit two: A Grand Don't Come For Free by The Streets.

These two albums have enough in common for them to suggest a trend of a kind, but their differences are equally telling. Both are second albums, follow-ups to smash hit debuts, 'sophomore' efforts, well known to specialists as 'difficult' (you spend a lifetime preparing material for album one, six months - during which you are primarily doing promotional tours for the first album, to come up with the material for album two). Each has responded in his own way to this challenge. Showtime follows Boy in da Corner, the debut album by teenage East Londoner Dizzee Rascal (aka Dylan Mills), which won the Mercury Prize - UK music's chin-stroking accolade, an aficionado's seal of approval. It also sold very well, at least in the UK, in quantities unprecedented for British hip hop. A Grand Don't come for free is the second album from Mike Skinner (who calls himself 'The Streets') the follow up to his debut of last year, Original Pirate Material; which gained much, as they say, critical and popular acclaim. Dizzee Rascal is from Bow, east London and is black. Skinner is from the Black Country and isn't black at all.

Both records have a potent sense, a stench, of place, but the places are different. Dizzee Rascal's rapping is reminiscent of nothing less than the top deck of a crowded bus through Peckham at four o'clock on a weekday, thronged with over-loud black school kids shouting, flirting, threatening, bleeps zinging out from numberless mobile phones. Dizzee's musical milieu is the cradle of 'Grime' the British genre which, while using hip hop production techniques - scratching, breakbeats, sampling - owes as much to Jamaican dancehall, and Miami bass, acid house and Belgian techno as it does to New York hip hop. Grime resignifies hip hop not as the consumerist bling bling soundtrack to upward mobility, but as the cri de couer of the dispossessed, the narrative form of urban life; what Chuck D of Public Enemy called 'black people's CNN'. Simultaneously it amplifies and manifests the connections between hip hop and the post-rave musical forms that are this rainy island's gift to global clubbing - drum and bass and UK Garage/two-step.

Although Skinner comes, to some degree, out of the same milieu, he has taken a different approach. Rather than emphasising the local, the place, his album is a kind of ballad of no-place, anyplace, Nowheresville UK. Listening to Mike Skinner transports you to the almost deserted top deck of the replacement bus running between Manningtree and Harwich town on the Ipswich-Liverpool Street line, at 11.20 on a Sunday evening, while two hair-gelled teenage boys discuss how mashed up they got last night, and the party where someone copped off with one of their birds, smoke, fiddle with their mobiles, yell from the window at passing mates, and fantasise about how they will wreak a terrible revenge on the miscreant after woodwork.

Dizzee Rascal's world is based around the urban setting of multiracial Bow - the closest Britain gets to an Americanised ghetto. Skinner's is distinctly sub-urban - the land of asbos, twockers and daytime drinkers. Both artists have found distinctive ways to render their surroundings sonically, through word, accent and music. The effect in both cases is produced, refreshingly, through the combination of lyrics and beats, words and music. Both produce their own musical background, drawing on a sound palette that owes very little to hip hop production as conventionally understood- very few jazzy or soulful references, few conventional break beats - but very much to the musical forms which have sprung up and flourished in Britain since acid house in the 1980s, which have allowed British dance music to break free from American form, and given, finally, these young 'rapper-musicians' the confidence to step out from under the shadows of America's dominant rap stars. Neither tries to sound American and nor does the music they speak over.

Dizzee Rascal and Mike Skinner have reacted rather differently to the challenge of the second album. Showtime sees Dizzee moving, but not too far, from the booming sub-bass, grating beats and gothic realism of Grime proper, towards a slightly more radio/video friendly sound. This seems at present to be working - both by allowing him a place in the charts, and on MTV, while maintaining the loyalty of his urban fan base, and attracting new converts on the American alternative circuit.

Narratively the street tales of Boy in Da Corner, has shifted with Dizzee's new found status - less emphasis on life in the estates, more on how it feels to be successful and how people might react to that. At the moment the tension between stardom and the street, pop success and underground credibility, are held tight in a productive tension by the controlling authorial voice - compelling and annoying as it is - and the musical nous.

If Dizzee Rascal has moved outside his immediate environs - as he starts to tour and expand his horizons - Mike Skinnner has retreated: from stardom, from dance music, from 'the streets'. The setting for his record, which is a kind of reality TV soap opera set to music - a story primarily of love and loss (of a girl and a box full of money), with a cute alternative ending like Sliding Doors - is inside, on the couch, in a nameless pub, or (in the best track of the album, 'Blinded By The Light') a dodgy club. Throughout we are inside the mind of Mike, a shiftless, hapless, every-teen. His delivery is what critic Simon Reynolds calls 'unwieldy, yet strangely funky', consciously natural, annoyingly appealing. Musically Skinner has retreated from the big beats and hooks of Original Pirate Material, toward a film soundtrack influenced blend of beats, pianos, strings and horn stabs. His sung choruses are more reminiscent of Squeeze, Elvis Costello or Madness than hip hop or soul, but there's no mistaking the art involved, the originality, the cleverness, the Englishness of it all.

So Dizzee Rascal is the most quick-witted, verbally sinuous, and musically gifted rapper to emerge from urban Britain, yet. Mike Skinner is the hip hop balladeer of the suburbs, an anthropological humanist (as one review had it) marking the unlikely connection between Norman Wisdom, Suggs, Seinfeld and Del Tha Funkee Homosapien. They are the saviours not only of British hip hop, but of contemporary British popular music. There, I said it. I hope their careers can back me up.