The returns queue gets longer and so does the wait – considerably longer than the 69 minutes of programmed music in this the second of the Daniel Barenboim Beethoven/Schoenberg series. But what a satisfying two–course meal it was: Schoenberg’s “transfigured night” of desire and confession, Verklärte Nacht, and Beethoven’s grandest piano concerto, No 5, “The Emperor”.

Anyone who can sell out four concerts of Beethoven and Schoenberg, even if it's only half-scary Schoenberg, surely looms large in the public imagination. Daniel Barenboim is a great humanitarian figure, and has been a thought-provoking interpreter of the classical and romantic piano repertoire for nearly 60 years, so it's not surprising that half of London wants to hear him in the Beethoven concertos. As a conductor, his natural element is earth; less so air, wind and fire.