Sketches of Corsica: the radiant lyric trumpet of Paolo Fresu glides across the massed voices of A Filetta, the singers who are both trailblazers and keepers of tradition in the realm of Corsican polyphony. The ancient and the experimental blend seamlessly in these compositions, several of them written by ensemble founder Jean-Claude Acquaviva, who has directed the singing group for more than 30 years. A powerful showing here also for Italian bandoneon innovator Daniele do Bonaventura, who contributes new music, solos imaginatively, duets with Fresu, and envelops voices and trumpet with an almost orchestral sense of form.