There are so many fine early music ensembles in the UK that there is barely enough work to go round. It's good, then, that the Lufthansa baroque festival gives us an excuse to hear visiting groups without feeling too disloyal - especially when they are of the calibre of the Freiburg Baroque Orchestra, and when the work they choose is as sunny and affecting as Handel's 1718 masque Acis and Galatea.

The work is very nearly a chamber opera, but its story of nymphs, shepherds and a jealous monster is static and tricky to stage: the only two dramatic events involve our hero being crushed by a boulder and then turned into a river. Its music, however, measures up to anything in Handel's more mature operas. Here the performers did it justice, although they were both helped and hindered by the acoustic, which flattered the choir and orchestra rather more than the soloists.

English Voices sounded larger and richer than a choir of 16 normally would, and put across every word. But the venue's churchy resonance turned the soloists' expressive touches into surges and swells, and so the subtleties offered by Sophie Daneman and Paul Agnew in the title roles might have come across better elsewhere. Still, Daneman sang Galatea's arias prettily, and though James Gilchrist's incisive tenor initially seemed to project more successfully as Damon, Agnew reinforced his lead tenor status with a dramatic account of Acis's Love Sounds th'Alarm. Alan Ewing made a lusty turn out of the monster Polyphemus.

Nicholas Cleobury was a late stand-in as conductor, but you couldn't tell. The orchestral playing, propelled by full-sounding bass lines that didn't wait for any stragglers, was as shapely as you could wish for, bringing a lilt to the slow numbers and to the faster ones a positive swing.

· The festival runs until Friday. Details: 020-7222 1061.