For a solo-piano recital, this one had unusually copious programme notes. The basics of Keith Jarrett’s illustrious career, his vast discography and numerous international honours, covered two A4 pages of fine type. But buried deep among these stats was one salient phrase: the great pianist’s ability to “listen in the moment”.

Making major creative decisions on the hoof is probably Jarrett’s greatest gift, and one suprisingly uncommon in an art form supposedly dedicated to the primacy of improvisation. In practice most jazz stars, even in”free-improv,” build a vocabulary of stock phrases. Not so Jarrett. Whether playing standards or free-associating, he avoids cliches, is constantly unpredictable and never resorts to nonsense.

Always a bundle of nervous energy, he found the first half a tense affair. Early on a customer coughed very loudly, and the slim, greying American stopped. Peering over his John Lennon shades, he glared at the offender. “All right,” he snapped. “Now let’s all cough and be done with it.” Settling down with difficulty, he dabbled in a variety of moods and rhythm patterns, producing some pleasant miniatures but nothing that really left the ground.

The second half, as so often, was much better. This time a cameraman’s red light upset Jarrett but it also recharged his batteries. “What is it about society,” he yelled, “that demands an image?” Playing more vehemently now, he was suddenly choreographing his music as of old, rising from the bench to a half-crouch, knees bent, with his head craned sideways and his face contorted by strange groans and sighs.

At last chord changes were heard. Jarrett knows thousands of them and voices them more subtly than anyone else. A sumptuous ballad was followed by a superbly judged piece of gospel-blues that finished at exactly the right moment. The applause was long and loud, and the encore, a pristine version of his ECM favourite, My Song, was perfect. Everyone left with a smile, even the highly-strung Mr KJ.