Performed a heroic deed: rose at half past seven in order to be at the rehearsal for the symphony concert. Mengelberg is a first-class conductor, and is also a lucky man: he has short arms so can make whatever gestures he wishes without the fear Tcherepnin or I are always subject to, that he will end up flailing around like a windmill. Mengelberg presented a vivacious account of Glazunov's Fifth Symphony, a better piece than the Seventh. I know it well, and listening to it gave me pleasure. Strauss's Don Quixote is not, of course, music at all. But it has much of interest in it, achieved with skill and humour: the bleating of the sheep, the characterization of Sancha Panza, the episode with the pilgrims.