Every good festival has its own identity. So it is with Manchester Jazz Festival. The 15th MJF, like the first, back in 1996, is strong on individuality. The policy of the MJF promoters (Steve Mead and Mick Waterfield) is inclusive enough to embrace Zimbabwean songster Papa Miles (St Ann's Square, Sunday 25, 1pm) and Goldfrapp-wannabe Rodina (Festival Pavilion, Tuesday 27, 8pm). Traditionalists and mainstreamers might grumble, but the Festival reinstates the definition of jazz as "the sound of surprise".  

As ever, the programme mixes homegrown talents with players of national and international renown. Local tortoises often compare favourably with celebrity hares.

Jim Hart: Chetham's Class of '96

Of course, the distinction between tortoise and hare is sometimes subtle. Gwilym Simcock - playing with UK/US supergroup Simcock/Walker/Swallow/Nussbaum (RNCM, Tuesday 27, 7.30pm) - and Jim Hart, playing with NY trumpeter Ralph Alessi (Festival Pavilion, Friday 23, 7.30pm), met and started playing together when both were students at Chetham's School of Music (circa '94-'96). 

"I love Manchester. It's one of my favourite places," says Hart, a vibes-player of blinding momentum. "I always said I would go back, if things didn't work out in London, but I seem to have got stuck." 

  

And Arun Ghosh's appearance, co-starring with the Asaf Sirkis Trio (BOTW, Thursday 29, 9pm), is virtually a homecoming for the charismatic clarinet-player. Ghosh, "conceived in Calcutta and bred in Bolton", is currently making waves in London with his unique brand of Mancunian Indo-jazz. 

"It needed to be done," says Ghosh, of his move to London, "to get a fresh outlook. But I learned everything I needed to learn while I was in Manchester." He identifies a specific Manchester aesthetic: "The main thing is that sense of wanting the music to be accessible. If you're going to go on-stage and play, you have to believe in what you're doing, and say it with conviction." 

Arun's fervour is communicated not only through his clarinet, which is stately and joyous, but through his body language (sashay and sway as much as swagger). Ghosh has been known to transport a rowdy crowd at Matt and Phred's to an altogether loftier place. His attack is gentle yet rigorous, and his simple tunes - often revolving around an Indian-style twelve-beat cycle - grow in detail, complexity and intensity until even the most inattentive onlooker is compelled to listen. "Yeah I think Man United had played that night," says Ghosh, reminded of the occasion. "I feel we can win people over, if I have the right people with me, because we believe in what we're doing."  

The right people for the MJF gig are Manchester rhythm team Myke Wilson and Sylvan Richardson, Corey Mwamba - a whirlwind on vibraphone - from Derby, and London saxophonist Idris Rahman ("you hear Ornette Coleman and Don Cherry weave lines in and out of each other, and that's something we're doing a lot," says Ghosh). More than an ex-pat, Arun Ghosh is an ambassador for Manchester. 

His erstwhile sparring partner, saxophonist Nat Birchall, shares half the bill (BOTW, Friday 23, 8.30pm) with Marshall Allen, a mainstay of the Sun Ra Arkestra. "I'm honoured to be playing the same night as Marshall Allen," says Birchall. "He's one of my all-time favourite players." 

Birchall is one jazz musician who stayed. "I don't have much experience of jazz anywhere other than Manchester," he admits. His music draws on the gentle side of John Coltrane for inspiration. The new album, Guiding Spirit, is rapturously lyrical, and too beautiful not to be spiritual, with an urgency that keeps it from being merely pretty. 

The realities of the jazz life haven't altogether dispelled Birchall's sense of high purpose. "Once you're determined to follow a certain route, you're got to make the best of it. Sometimes you're lucky to be with like-minded players. Other times you're working in adverse conditions, but you carry on and do it anyway. I always try to put everything into it, and play with soul and feeling." 

Not as overt as the Coltrane influence, Birchall's first love is ska/reggae. Armed with this knowledge, Guiding Spirit takes on an entirely new light. Pioneering JA hornmen Tommy McCook and Cedric Brooks had a direct, uncluttered eloquence that feeds directly into Birchall's style. Similarly, the harmonically simple themes and hypnotic basslines are retentions from a golden age of Jamaican music. It seems that the secret of finding one's own voice is to wait, however long, for your influences to crystallise. In Birchall, the formative passions of the youthful reggae fan are mysteriously reconfigured in the mature musician. "A saxophone player's sound is largely determined by the sound we have in our heads," he says. "I'm getting to the stage where I can say the music is 'pure', in the sense that it manifests itself through me, without my conscious mind affecting the outcome." 

Other prophets without honour include Neil Yates, whose Surroundings (St Ann's Church, Saturday 31, 7pm), a commission from MJF, is a piece for full orchestra with a starring role for St Ann's Church itself. With the instruments scattered around for antiphonal effect, the building, with its unique acoustic and sacred ambience, is the star turn of Surroundings. 

Zoe Chiotis: A slinky siren... 

Pianist John Ellis is versatile enough to handle any musical situation - here he's accompanying Zimbabwean Papa Miles - but he is also a composer, a producer (the owner of Limefield Studio) and a charter member of the Odbod Collective, a top-notch group of Manchester creatives. Other Odbods include Zoe Chiotis, a slinky siren with spellbinding ways (St Ann's Square, Saturday 31, 5pm), and her stylistic opposite: the extraordinary Rioghnach Connolly, whose voice is so soulful that it seems older than her physical age by about three hundred years. The splendour of Riognach Connolly, a transplant to Manchester from her native Ireland, can only be hinted at here, so do see her with her band, Honeyfeet (Matt and Phred's, Friday 23, 10pm) or in a new group with Stuart McCallum (Matt and Phred's, Tuesday 27, 10pm). 

Guitarist McCallum, by the way, has blazed a quietly innovative trail with his loops, samples and pedals, and is so inherently Mancunian that London jazz critic John Fordham once mistook him for a Big Issue seller. He can also be seen with improvising trio Baylis/Howard/McCallum (Festival Pavilion, Friday 30, 12.30pm) and, later the same day, in a solo set alongside The Golden Age of Steam and trioVD (Festival Pavilion, 8pm). McCallum, a true homegrown guitar hero, might be the hardest working man in Manchester show-business. 

Carlton Club, Manchester, Monday 12 July 

The sound of Spaceheads occupies the margins between trance dance, free jazz and psychedelia. It comprises of Andy Diagram's blissed-out trumpet - electronically enhanced by loops, echoes, octave doubling and fractal patterning - and Dick Harrison's drums, locating rhythm and pulse with every crash and bang, and serving as the perfect launchpad for Diagram's kosmic klaxon. 

They've been away for too long, doing things that come to all of us in time - raising families, planting trees, reforming James etc. So there was a preponderance of old tunes in the set, and a welcome chance to revisit dislocated dancefloor faces like Trance Figure 8. 

Improvising comes as second nature to Spaceheads, and the search for fresh discoveries began in earnest when the duo were joined by Orchestre Marcel Duchamp's Vincent Berthelet on bass. Making fresh discoveries and striking vital grooves are not mutually exclusive activities for Spaceheads. It comes as a shock to realise that Diagram's tabletop of wires and wonder, so state-of-the-art twenty years ago, now seems actually primitive. Older spectators may feel nostalgic for a time when rave culture could embrace two men armed with technology, brio and imagination, intent on replicating the impact of Bitches Brew with just trumpet and drums. Their light show, meanwhile, was quaintly redolent of Pink Floyd at Middle Earth, circa 1967.

The sensibility of headliners Orchestre Tout Puissant Marcel Duchamp is post-punk, and the instrumentation is appropriately bizarre - trombone, marimba, fiddle, guitar, drums and double-bass. Their surreal affiliations are not only signposted by the name but by a resolute rejection of all musical and social convention. Singer and violinist Liz Moscarola is the model of charming, aggressive femininity, alternately little-girl-lost and barking. She proclaims emotional vulnerability in evocative yet oblique stanzas. I didn't understand a word ("the house is coming"?) yet was profoundly moved. The rhythm team of Anne Cardinaud and Wilf Plum generated a clattering yet well-calibrated groove. Big-toned trombonist Seth Bennett is one of the loudest brass men in the business: conversely, the light-toned guitarist Mael Saletes is one of the quietest grunge guitarists in the business.   

Orchestre Tout Puissant Marcel Duchamp are surreal in the true sense: more than art, it's a way of life; of living on the edge of your senses. The players perform with a conviction that, in other circumstances, would be dedicated to fringe religion. And their music defines the epithet so beloved of Patti Smith: 'beauty will be convulsive or not at all." Very romantic. Very subversive. Very Gallic.