Chick Corea and Bela Fleck, Barbican, London

Chick Corea has been on many strange musical journeys, but pairing his piano with a banjo may seem a uniquely odd combo. Bela Fleck, however, is no good ol' boy chewing on a piece of straw as he picks away.

Of Hungarian origin, he's recorded works by Debussy, Chopin and Paganini and toured with two fellow supremos of the strings, the violinist Jean-Luc Ponty and the bassist Stanley Clarke. (And, yes, he has committed occasional acts of bluegrass. At least it's not as bad as country and western.)

Some say he is the finest banjoist alive today. That sounds like a limited compliment only until you witness the virtuosity of his guitar-fingered technique and the subtlety and clarity he coaxes from what is not generally thought of as a serious instrument.

Fleck and Corea found instant common ground in the stark Spanish-tinged harmony of their opening number. They alternated the role of accompanist, allowing both to take short solos in a beautiful semi-classical composition that would be more at home echoing in the pillars of an ancient cathedral. Deceptively effortless – and clearly intricately arranged – passages formed bridge sections and concluded the piece.

Another began in a similar way with solo statements responding to each other, although at first this came across as undoubtedly brilliant but baffling. This highbrow preamble over, the pair launched into what turned out to be one of several riff-based numbers. Many of these were mainly in one key, allowing the performer a freedom that beginners often find frightening – how do you avoid repetition without the comfort of changes to fall back on? For master improvisers, however, it allows great space and time, either for contemplation or to start off on a quest.

The pair also demonstrated great humour, Corea spending several minutes explaining a complicated joke, or goofing at the piano while Fleck was retuning a string. Perhaps because he has nothing to prove, he is able to relax and just enjoy whatever it is he wants to do, a characteristic shared with his contemporary Herbie Hancock.

Corea is tremendously versatile, the downside of which is that you can never be sure what you'll get. Duetting with Bela Fleck, I can report, you can be sure of catching Corea at his urbane, intelligent best.