Past years at the Cheltenham Jazz Festival have featured Jerwood Charitable Foundation-supported artists in either a Rising Star category or performing specially commissioned material; on this occasion, the Jerwood remit was broadened slightly to accommodate music commissioned by other festivals, or written for other occasions, thus granting it a new lease of life and enabling the artists concerned to develop and reinterpret it.

The set performed by Phil Robson's Six Strings and the Beat was originally commissioned by Derby Jazz, and has been performed a couple of times at the Vortex already (most recently on May Day); it's a wide-ranging selection of music for two violins (Emma Smith and Jenny May Logan), viola (Naomi Fairhurst), cellist Kate Shortt, bassist Peter Herbert and drummer Gene Calderazzo, along with composer/guitarist Phil Robson, and touches bases as apparently widely dispersed as Malian music, fluid post-bop, blues and all points between, but coheres beautifully, courtesy of Robson's skilful and uncontrived deployment of his unusual musical forces.

His strings, of course, are by now highly experienced in such situations (in bands run by the likes of Ben Davis and Christine Tobin, to mention just two), so their jazz soloing and comping sounds entirely natural, and with Herbert and Calderazzo driving the whole with eloquent power and considerable subtlety, the band, despite its unique configuration, is a wonderfully tight unit as a consequence.

It is Robson himself, though, who shines throughout, both as an extraordinarily versatile composer and an utterly compelling soloist, moving unaffectedly from blistering single-note boppish runs to raunchy blues playing and delicately tripping African-style guitar to the almost sound-sculpture world of, say, Terje Rypdal or Bill Frisell and all performed with the ease and natural grace of the unassuming virtuoso he is. The forthcoming Babel album featuring this music is eagerly awaited.

Another Jerwood JazzGeneration gig followed immediately: Outhouse Ruhabi featured the London-based jazz quartet Outhouse (drummer Dave Smith, bassist Johnny Brierley, saxophonists Robin Fincker and Mark Hanslip) and a Gambian percussion group, Sabar Drums (Baboucar Camara, Biran and Mambiran Saine, Kaw Secka and Laity Fye).

Vortex patrons will already be familiar with the former outfit, who usually dispense a raw and vigorous mix of free-ish jazz and heavy riffs, but in this company they adapted their sound sensitively to the demands of the driving, whip-smart but roilingly exuberant sound of the Wolof drummers.

Breathtaking precision and passionate energy characterise Sabar Drums' approach, and it was fascinating to hear Fincker and Hanslip folding their respective tenor sounds into the percussion mix, producing in the process music that was clearly the result of close mutual attention and respect.

Laity Fye, too, proved to have a spine-tingling vocal talent that brought the likes of Salif Keita to mind, and overall this was a triumphant vindication of the practice of musical travelling and study (as opposed to the more usual article, musical tourism). The band can be caught live again at various UK venues during May; (see www.bbc.co.uk/africabeyond/africaonyourstreet or www.loopcollective.org for details); they come heartily recommended.

Club patrons will also be familiar with the viscerally exciting, high-energy music produced by the various bands led at the Vortex over the years by US saxophonist Tim Berne. On this occasion his quartet, Science Friction (keyboardist Craig Taborn, guitarist Marc Ducret, drummer Tom Rainey), produced Berne's customary heaving, volatile mix of raw freedom and pounding precision, with perhaps a little more emphasis on the latter than usual, courtesy mainly of Rainey's trademark skill at combining brisk assertiveness and subtle accommodation of his fellow players.

Taborn, as ever, proved adept at selecting suitable keyboard timbres; Ducret produced an astonishing variety of guitar textures both in accompaniment and in solo passages; Berne roared and squealed as required the whole was an irresistible, entirely satisfying barrage of structured and free sound, demonstrating just why Berne is a uniquely inspiring figure for so many contemporary jazz musicians.

The Dave Stapleton Quintet is another band which will be familiar to Vortex habitués, their albums and live appearances alike marked by leader/pianist Stapleton's ear for a catchy riff that contains just sufficient wrinkles to support improvised explorations, but which is also accessible enough to hook and retain an audience's attention.

Sparky and lively, with trumpeter Jonny Bruce in particular catching the ear with a series of flaring solos, the band performed a selection of pieces from their two albums, When Life was in Black and White and The House Always Wins. In a more ethereal vein was the music of Alias, an Anglo-Swedish quintet comprised of Iain Ballamy (tenor), guitarist John Parricelli, bassist Palle Danielsson, trumpeter Staffen Svensson and drummer/co-leader Peter Danemo.

Ingenious use of textural variety, delivered with poise and elegance, was this band's hallmark, Ballamy's thoughtful, lyrical saxophone playing setting the tone perfectly for a set of wide-ranging but coherent originals, specially commissioned by Jerwood for this festival. Cool and meditative, but with just enough backbone to support its delicacy, this was 'European' jazz of the first water, with Parricelli alternately swooning and chiming in support of the two horns and the gently pattering but consistently eloquent rhythm section. A relatively understated but none the less powerful performance.

Sunday began with a Birmingham-based group: the Dan Nicholls Band. Nicholls himself has a wide-ranging ear that has clearly listened to everything from Tim Berne to Indian music, and this eclecticism is everywhere evident in his widely varied compositions.

With Robin Fincker making his second festival appearance on tenor and clarinet and the leader himself contributing careful piano and occasional electronics, this was an absorbing set of original material, the slight self-consciousness of which will no doubt dissipate as the quartet relaxes with increased live exposure. Nicholls is clearly a considerable compositional talent (an Indian-flavoured piece inspired by his tabla teacher was especially impressive), and this gig whetted the appetite for a more informal gig in a club setting.

Jack DeJohnette was billed as a solo act, and he began with an intriguing improvised piece involving a number of small cymbals, smartly struck and cleverly amplified with a hand-held mic, plus percussion effects similarly processed, so that the overall effect was of a drumkit-generated soundscape.

He then drummed a tribute to Motown's stalwart rhythm section, Benny Benjamin and James Jamerson which, by considerably outstaying its welcome (the Tamla beat, after all, is designed solely and selflessly to buoy superb pop music; arguably, its effect is spoiled if you focus too readily on it), caused his performance's momentum to slacken with its robotic repetitiveness.

Luckily, though, he had an ace up his sleeve in the form of Ravi Coltrane, with whom he performed a couple of rousing duo improvisations, DeJohnette himself operating on both drums and piano, and Coltrane playing intelligently varied tenor.

Bobby Previte's New Bump like all Previte's various bands over the years simply bristled with energy, the leader/composer's drums joyously driving his cleverly shifting themes, attaining a series of controlled but rumbustious climaxes that somehow contrived to be both highly quirky yet quintessentially Previte; he has an unmatched talent for producing both slow-building, haunting melodies that seem to hover in the air (making them sound like film themes they even have names such as 'Were You Followed?') and more straightforward, bustling material.

On this occasion, unusual textural variety was added to the Previte mix, courtesy both of Bill Ware's shimmering vibes and Ellery Eskelin's free-jazz-rooted tenor playing, which brought a highly effective abrasiveness to the band sound. 'Electrifying', 'sparky' and 'intelligent' were the adjectives applied to Previte's music in the programme; he delivered on all three.

With a name like This Against That, trumpeter Ralph Alessi's band might have been expected to produce somewhat abstruse, intellectualised music, but while the thoughtful meanderings of pianist Andy Milne, the carefully considered spearing sound of Alessi himself and the ruminative yet impassioned tenor of Ravi Coltrane did occasionally imbue their performance with an air of earnestness, the overriding impression was of seriousness in their search for an individual approach to producing a fresh sound from conventional jazz-quintet forces.

Like Alias before them, they seemed as interested in texture as in straightforward propulsiveness, but with bassist Drew Gress and drummer Mark Ferber constantly probing for original ways of pushing the band through Alessi's intriguing themes, momentum was never compromised, just inventively disguised. This was thoughtful music, impeccably performed.

With a name like The Final Terror and their leader, Pete Wareham, wearing a tee-shirt featuring a heart dripping blood with a dagger through it, the quartet comprised of Wareham (tenor, baritone, electronics), Chris Sharkey (guitar), Ruth Goller (bass) and Leo Taylor (drums) were never going to be anything but loud and uncompromising, and as at their debut in April at the Vortex, an occasion Wareham ('this is our first ever gig') seems, worryingly, already to have forgotten they lived up to their name and reputation with a fierce collective thrash full of buzz-saw electronic noise, relentlessly pounding bass and drums and screaming, wailing tenor playing from Wareham over looped baritone riffs.

As in late-1980s Bill Frisell gigs, say, Wareham spent a little too much time fiddling on the floor with electronic gizmos, but when they went for it (which they did for most of the gig), Final Terror were well nigh irresistible, a considerable force, and they provided a telling contrast to the previous band, demonstrating in the process just what a wide church contemporary jazz is.

The aforementioned Bill Frisell filled the Everyman Theatre for the first time in the weekend, and justifiably so. He has wandered gently away from jazz of late, into country music, rock and African music (to name but three byways he's been exploring), but this band tenor player Chris Cheek, cornettist Ron Miles, bassist Larry Grenadier and drummer Rudy Royston is the closest Frisell has come to re-creating the multi-textured, jazz-based sound of one of his most musically successful outfits, the 1996 quartet completed by Miles (who played piccolo trumpet and normal trumpet then), violinist Eyvind Kang and trombonist Curtis Fowlkes.

Squeezing out mesmerising solos from his electric guitar (with little pedal-fiddling and no banjo etc.), and deploying his beautifully contrasted soloists with graceful skill, Frisell guided his capacity audience through what amounted to a tour d'horizon of jazz, from swing and bop, to free and contemporary sounds, with a little soul thrown in.

One minute his band were bouncing exuberantly through slightly askew bop-type themes or even swing-type numbers, the next they were indulging in the subtlest free interplay tellingly interspersed with wonderfully cogent soloing from all the front-line players.

With Royston and Grenadier providing flawless rhythmic support throughout, this was a superb display of utterly contemporary but deep-rooted jazz and the band came the closest of all the abovementioned acts to doing something that used to be taken for granted at jazz festivals playing a standard when they lingered exquisitely over the affecting Sam Cooke classic, 'A Change is Gonna Come'. Perfection.