The Vaughan Williams, which sets lines from The Merchant of Venice, was the perfect opener for the occasion, its wistful melodiousness just joyous enough, and showcasing four distinctive soloists. The BBC Singers, high up in the choir stalls, added to the moonlit atmosphere with disembodied voices off that belonged more to The Tempest. Poulenc’s Organ Concerto was the work that you won’t hear anywhere else – every good Proms programme has one. It’s a curious piece, gothic and severe one moment, delighting in souped-up harmonies the next. Daniel Hyde tamed the beast that is the Albert Hall’s 9,999-pipe organ, revelling in the instrument’s possibilities yet always in conversation with the BBC Symphony Orchestra’s strings.