Over the past six weeks of the Proms the BBC’s hard-working Symphony Orchestra has performed everything from Britten to Brahms, Verdi to Volans. Their Mahler with Ed Gardner was an operatic epic, their programme of English music for Mark Wigglesworth glowed with wit. Yet hearing their ragged and unlovely account of Beethoven’s Ninth Symphony last night it was hard to remember their triumphs, hard even to remember the delicate account of Graham Fitkin’s new Cello Concerto that they delivered in the first half, so complete was their collapse.