Antonio Vivaldi wrote most of his choral music for the all-female orphanage Ospedalle della Pietà in Venice, where he directed the musical activities for almost 40 years. Vivaldi's sacred music exudes the same spirited drive and dramatic virtuosity that have made his concertos so popular. The young women of the Pietà chosen to perform in its choir were renowned for their exceptional musical abilities and angelic voices, and their concerts quickly became a popular tourist attraction in the 18th century. It is unclear whether these girls actually performed the bass parts, though there are a few tantalizing--if unintuitive!--contemporary references to just such a practice There is no consensus on whether the lower voices were sung as written in the score--most modern renditions feature a mixed chorus--or whether they were transposed up an octave. Matthias Maute, conducting Ensemble Caprice, makes an inspired case for the latter approach--his all-female choir sounds, aptly, angelic.