Only one thing precludes this CD of superb baroque arias by Porpora, Hasse, Galuppi, and others from being a five-star rave, but it's a irremediable: mezzo-soprano Vivica Genaux's almost constant old-fashioned vibrato. Genaux has a gorgeous voice; it's her training that went awry. She patently needs that vibrato to sing "in tune', or rather to deal with slightly inaccurate tuning. In the few phrases of the Porpora aria when she lets the vibrato go, she is often flat. If you want to hear why the vibrato is unacceptable, listen to Philippe Jaroussky's CD of Arias for Carestini, Farinelli's great rival, or to any of various recital CDs by Sandrine Piau or Gerard Lesne.
Otherwise, it's an excellent performance and interpretation of first-rate music. Rene Jacobs and his Akademie für Alte Musik Berlin plays flawlessly and energetically, but nothing they do can compensate for the vocal wobble. I've been satisfied with Vivica Genoux's contribution to ensemble recordings; a full solo CD, however, is a career mistake.