And Previn was as jazz-friendly as someone who once shared a record label (Los Angeles's Contemporary in the 1950s) with Art Pepper and Ornette Coleman has a right to be. Disdaining the flash of an Oscar Peterson or a Phineas Newborn, he proceeded by oblique strategies, altering the pulse when he wanted to, playing harmonic games, rattling off a staccato flourish here and there, and never once looking as if a bead of sweat might disturb his floppy grey coiffeur. His solo on "Satin Doll" was a marvel of concision and elegance, the right hand taking the line of the melody for a slow but circuitous walk that became gradually more daring as it progressed, graphic arabesques leading into almost abstract squiggles which were then resolved back into the likeness of the governing chords without ever threatening the tranquil surface of the tune, or our indulgent, pipe-and-slippers mode of listening.
If there were to be any crossover correspondences from classical to jazz, Previn revealed his late Romantic enthusiasms in the few ballads of the programme, approaching a slow version of "I Can't Get Started" with a delicate, even Viennese intensity. He could sound rather stiff and formulaic too, as a plodding version of "Old Man River" proved. But the audience loved him; every time their collective unconscious recognised the opening of a tune a ripple of applause rang out as if he had written it himself. At the end the reception was deafening. But it was 9.30pm precisely and time to go home. Bud Powell, of course, would have played on till dawn, but he probably didn't have a home to go to, and Previn had already shown us how very good a jazz pianist he is.