Friday night’s Sydney Symphony treat at the Opera House’s Concert Hall was a sold-out affair. The audience sizzled with expectation at the prospect of hearing a ‘world celebrity’. Daniil Trifonov was in town ‘performing Rachmaninov’, as the informative program’s cover proclaimed. But which Rachmaninov? Well, it was Trifonov’s favourite among Rachmaninov’s four concertos: the Fourth.