Sir Thomas Beecham once found himself conducting a rehearsal of Sibelius's Lamminkainen. "In this piece," he told the orchestra, "you may find it a matter of some difficulty to keep your places. I think you may do well to imagine yourselves disporting on some form of hair-raising locomotion such as Brooklands, or a switchback railway. My advice to you is merely: hold tight and do not let yourselves fall off. I cannot guarantee to help you on again."