Mezzo Cecilia Bartoli could easily rest on her laurels as one of today's most charismatic, character 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 tantalising 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 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 theatres of his time and the arias gathered here demonstrate the word-painting magic of his music, from the sylvan setting of duetting 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 colour of her phrasing is wonderfully matched throughout by Il Giardino Armonico's lively panache. All power to Bartoli in her goal of reviving this neglected aspect of Vivaldi's output. -Thomas May.

Fans of Karl Jenkins' Adiemus albums or of Enya's mix of voice and synth sounds will find much to admire in this recording. On Libera, a boys-voice choir achieves ambient ethereal effects by judicious close-microphone work and liberal use of distant-sounding reverb programmes. The music is all by the choir's director, Robert Prizeman, whose church-music background has served him well-the close-harmonisations are rather graceful and are ably performed by the boys, even in the high ranges in which they are often required to float. The only two pieces not by Prizeman are arrangements of the famous canons by Pachelbel and Tallis, which he cunningly works into two of the tracks. The vocal writing is supported by a modestly trippy synth background and a light beat. The words are taken from traditional devotional texts (Beata Lux, Dies Irae, Agnus Dei, and so on) but the overall effect is less religious than chilled. -Warwick Thompson.