Mezzo Cecilia Bartoli could easily rest on her laurels as one of today's most charismatic, characterful singers for her lively portrayals of Mozart and Rossini heroines. But it's been particularly exciting to observe her growth as an artist in exploring the exuberant world of baroque opera, with its range of pyrotechnic demands--both vocal and emotional. Bartoli's show-stopping virtuosity in a Vivaldi aria from her Live in Italy recital gave a tantalizing sample of her finesse in that style. For The Vivaldi Album, Bartoli conducted extensive research into the composer's manuscripts, (a documentary tracing her quest is planned for subsequent international screening). Although he's best known for his concertos--in typically baroque fashion, two of the arias in fact recycle material from The Four Seasons--Vivaldi was a ferociously prolific composer of operas for the cutting-edge theaters of his time, and the arias gathered here demonstrate the word-painting magic of his music, from the sylvan setting of dueting flageolets in "Di due rai languire costante" to the storm-tossed passions of "Anch'il mar par che sommerga," where Bartoli spins out ripples of rapid-fire coloratura with a gravity-defying accuracy that will leave your head spinning. In addition to many such examples of vocal acrobatics, Bartoli brings exquisite nuance and limpid tone to the delicate echo effects of "Zeffiretti, che sussurrate," and there's no better test for the remarkable flexibility of her range--full and dusky at the bottom and thrilling at the top--than the huge intervallic leaps of "Dopo un'orrida procella." With her naturally large voice, Bartoli can at times tend to histrionic excess (in the recitative to the short aria from "L'Orlando finto pazzo"), but the expressive color of her phrasing is wonderfully matched throughout by the Giardino Armonico's lively panache. All power to Bartoli in her goal of reviving this neglected aspect of Vivaldi's output. --Thomas May