And yet when the time came for his fiery first entry he turned on us with a vengeance, stamping wildly and forcing his tone almost to the point of ugliness. Then came the magic, that wonderful first theme, which floated past us as if in a dream.
But the contrasts with the first movement's more assertive passages were too violent, too overtly theatrical. Three-quarters of the way through the movement the violinist goes his own way for an unaccompanied cadenza. Again, Kennedy thrashed mercilessly until that theme came back and the devil in him turned into an angel.
The first movement was tailed by a grateful round of applause, then he turned his back on us again for the lovely oboe solo that opens the second movement. This time Kennedy actually started to play to the orchestra, turning to us only after the first few bars. He kept the musical line bright, narrowing his tone to a silver beam, then applying the pressure as and when Brahms asked him to. The movement's closing pages were pure poetry.
But it was the finale that really took off. If there's a gypsy in Kennedy's soul, this was his moment. Daniele Gatti's characterful conducting added to the mood of rustic abandon. The Royal Philharmonic's strings revelled in Brahm's beefy melodies and for onceKennedy's stamping fitted the mood of the moment. When the concerto had finished, the audience went mad, and he gave us some Bach - the last movement of the third unaccompanied Sonata. He signed off by extolling the virtues of his musical partnership with Gatti and the RPO.
What a contrast to the opener - the sort of Beethoven Fifth heard 40 years ago, before modern scholarship deemed leisurely performances passe.
Beethoven needs to be confrontational, but last night's performance pussy-footed where others have made the earth move.