With last month's debut album release for his Unity Band, guitarist Pat Metheny introduced a saxophonist to his lineup for the first time in 30 years – the last occasion being the Ornette Coleman-influenced 80/81, with the late Michael Brecker and Dewey Redman. But the presence of the forcefully fluent Chris Potter on saxes and bass clarinet doesn't make the Unity Band any less of a Pat Metheny group, right down to their nimble fingertips. The band's long, single-set Barbican concert covered the album's tracklist (from rapid-fire postbop cascades through country-inflected ballads to exultant synth-guitar anthems) but it eventually added a good deal more, even if there was a 90-minute wait for some of the most musical and conversational exchanges between Metheny, Potter and the remarkable rhythm section of young bassist Ben Williams and drummer Antonio Sanchez.

The first hour variously cajoled and blasted its way through the album material, with Metheny gently opening proceedings with lyrical pieces on acoustic guitar and the harp-like Picasso instrument. The band then accelerated through rocking synth-guitar anthems and bluesy fusion, including the album themes Roof Dogs and Leaving Town, over Sanchez's surging pulse, and a yearning tenor-sax ballad that brought poised, shapely improvising from Potter and Metheny. The playing was often thrilling – Sanchez's first drum solo was a technical and dramatic masterpiece – but the ensemble sound was often remorselessly dense, and some of the themes lacked staying power.

In the later stages the show took off, sparked by a racing Michael Brecker theme and a series of lower-key duets. Metheny and Potter whirled through a delightful contrapuntal exploration of All the Things You Are, and Ornette Coleman's Turnaround was just as scintillating. Unlike the album, this was a balance of Metheny material and the jazz tradition. As a group of blazing virtuosi with musical intelligence to match, these four could make that chemistry work afresh for years.