This will be Christoph von Dohnányi's last season as principal conductor of the Philharmonia, an orchestra that, under his decade in charge, has often contended to be the best in the UK. Thus, it would be an unfair reflection of his tenure if the orchestra were to end its season without raising its game from the slightly-under-par level it seems to have settled in since its Queen Elizabeth Hall exile.

This season's opening programme was at least large-scale, and it reinforced the orchestra's commitment to the new, even if the first-half piece had its roots in the 1960s. Hans Werner Henze's opera The Bassarids was premiered in 1966, but four decades later he has reworked sections of it in Adagio, Fuge und Manadentanz. Even when paired with Beethoven's Ninth Symphony, it still seemed a work of immense scope.

Henze's three movements form a continuous 25-minute span, outlining the Bacchae story in microcosm. An elegant but sombre introduction gives way to some whirling dance episodes; with two harps and a celesta on one side of a packed platform and two pianos on the other, the orchestration occasionally out-glitters Ravel. Then the music turns percussively savage, before dissolving into a solo cello lament, ringingly played, though some orchestral moments could have used more panache.

As could pretty much the whole of Beethoven's Ninth; this was solid but stolid too, its third movement especially marred by sour wind tuning. Was Dohnányi offering a kind of minimalist interpretation, deliberately allowing Beethoven's detail to take second place to the all-important motor that drives the music - or was he just not looking out for the detail at all? Four classy but uncomfortable-looking soloists fronted an Ode to Joy in which the Philharmonia Chorus and Voices excelled themselves. But this couldn't compensate for a lack of joy in the interpretation as a whole.