One of the hallmarks of a great singer is the ability to transmute the most leaden material into pure gold, to make the most routine music seem a masterpiece. Symphony Hall was by no means full for Cecilia Bartoli's recital on Friday, perhaps because her programme - a 250-year survey of Italian song from Caccini to Donizetti - looked unpromising. But those who stayed away missed a treat, for Bartoli's belief in this unassuming music is totally infectious. Her ability to charge every phrase with dramatic purpose and to throw off the florid decoration with such dazzling charm, turned every number into a perfect gem.

Hearing Bartoli sing Caccini's songs made one long for her to tackle the operas of his contemporary, Monteverdi, while two cantatas by Vivaldi suggested that his operas might now be ripe for further exploration. Songs by Rossini and Donizetti were delivered as perfectly shaped miniatures, while in Rossini's solo cantata, Giovanna d'Arco, Bartoli finally unleashed her full technical armoury, cranking up the coloratura in the final aria with tremendous dramatic power.

Bartoli had been one of the stars of a concert performance of Handel's Rinaldo in Birmingham earlier this year, and she was on equally sparkling form in last week's London performances at the Barbican, again with the Academy of Ancient Music and Christopher Hogwood, but with a much-changed cast, in which the counter tenor David Daniels took over the title role, and the superb Bernarda Fink sang the trousers part of Goffredo. Daniels and Bartoli, arguably the two finest singers of our time, make an irresistible combination and they set the standard for an evening of remarkable vocal accomplishment from the whole cast, which managed to transcend the often ill-tuned orchestral contributions.