If all orchestras inspire a sense of loyalty to some degree, then the Philharmonia perhaps does it better than most. Mackerras is still performing with them, 54 years after he first conducted the orchestra; so is Maazel, who has clocked up 41 years, on and off. There’s Ashkenazy and Dohnányi. And then of course there’s Riccardo Muti, who appears to have been given the unofficial title of conductor-in-chief of anniversaries.