From the first arhythmic introduction from James Allsopp on tenor sax, quintet Fraud delightfully defied categorisation. Despite long passages of improvisation that felt like free jazz at its best, extended melody rose to the surface at times and organised riffs broke out, only to be subsumed into the background of another solo.

Playing in a way that seems mapped rather than scored, Fraud produce highly individual music that is full of great surprises. In the final two-part piece entitled Peripheral and Guzzle (an anthem to a dessert first observed and then eaten) the group moved from the quietly abstract to a full-on groove, employing the full weight of electronica and driving solos from all players, particularly Allsopp on tenor and Stian Westerhus on guitar. Without a jazz cliché in sight, there was superb tension and imagination. Sadly, the audience were not persuaded. When two of us applauded a solo we were drowned by the silence of our neighbours. This seemed perverse considering Fraud played to a packed and enthusiastic audience in the Vortex.

The second part of the evening, a duo of Corey Mwamba (pictured) and Orphy Robinson, was probably what had brought most people out on a cold evening. This was a great bit of pairing, not only because Mwamba has described Robinson as his mentor but also because, as vibes players, they have very contrasting styles. Robinson plays with a strong sense of rhythmic pattern that, with his powerful technique, he can maintain over a shifting melodic form.

Mwamba, on the other hand , approaches the instrument with the unexpected movements of a leaping gazelle, inserting phrases, chords, snatches of tune, until he reaches a pitch of excitement and attacks the full keyboard with enthusiasm, at one point even dislodging the keys. Looped rhythmic phrases that both players created on the fly provided a subterranean jungle and a sound world over which both could improvise. It was a magical experience to see these two work together, despite times when the tension drifted and background loop dominated.

An Oxford Contemporary Music event that hit the concept of contemporary right on the nail, this was inexplicably underattended. OCM have a number of equally fine events coming up. Check www.ocmevents.org for details.