The Academy of Ancient Music has in recent years become a propagator of new music as well. Premiered in Southampton in May but only now receiving its first London hearing, its latest commission is Thea Musgrave's Journey into Light, conceived as a companion piece to Mozart's Exsultate, Jubilate. The result is strong enough to stand up for itself in that pairing, yet a very different animal.

Instead of exhorting us to exult and jubilate, the soprano soloist sings 15th-century texts, thick with imagery, entitled Lament, Prayer and Contemplation. In the baroque-inflected cadences of the first and the birdsong fragments of the third, Musgrave revels in the plangent sonorities of the AAM's oboes and bassoon, but elsewhere the music falls into rich Wagnerian harmonies that suggest she would have been equally happy scoring the work for modern orchestra, had a commission been forthcoming - which in the case of Musgrave, one of the UK's most senior and underrated composers, is all too unlikely.

A larger voice than Carolyn Sampson's bright soprano might have suited the work better. Before the interval she had made a beautiful job of Exsultate, Jubilate, spinning through the florid writing with ease and making the first movement seem almost flirtatious. But though she communicated the texts of the Musgrave with dedication, there were times when the conductor, Paul Goodwin, almost let the orchestra overwhelm her.

The rest of the programme encompassed three symphonies from different periods in Mozart's career. K19a in F major, written when he was nine, bubbled exuberantly, though in the G major K129 the tuning among the first violins was a problem. But in K319, a zinging third movement seemed to loosen the players up and the finale sped by in mellifluous style.