On 5 August, Ferruccio Busoni’s Piano Concerto will be performed at the Proms for only the second time. It should have been the third time, but a Musician’s Union strike in 1980 forced the cancellation of the concert at which Martin Jones had been booked to give the première. Jones is a fearless virtuoso, still recording in his eighties, but one can’t help wondering whether his disappointment back then was tinged with relief.