Once you’ve spotted the secret, how do you “feel” it? This is a problem even when the secret is right there on the surface. Mostly we don’t even notice its presence – though I did spot one a few months back, in the Royal Opera House. It was during a performance of Strauss’s great opera Ariadne auf Naxos, at the moment where one character referred to death. Right on cue a trombone down in the orchestral pit played a solemn phrase. Why? Because for centuries the sound of the trombone evoked the solemnity of death. You hear that deep quality of trombones in 17th century composers like Monteverdi and Schutz and Purcell. It carries on through Mozart and Beethoven, right up to Bruckner. By the time Strauss wrote his opera in 1912, the tradition was nearly dead. That little trombone phrase could be its dying echo.