Paul Hillier’s intriguing blend of ancient and modern sacred music is something of a puzzle. In the absence of any explanation of his programming, the listener is left to join the dots between songs from the thirteenth-century Laudario di Cortona and contemporary works by Caroline Shaw, Julia Wolfe and Arvo Pärt. Helping listeners through this aural and conceptual intrigue is the constantly evocative singing of Ars Nova Copenhagen, which Hillier has directed since 2003.

Ars Nova Copenhagen

Hillier’s arrangements of six songs from the Laudario form the backbone of the program. This medieval manuscript from the Tuscan hill town of Cortona was discovered in 1876 by the local municipal librarian and contains spiritual songs sung by members of a Franciscan confraternity. (St Francis himself preached in Cortona in 1210.) These songs which celebrate themes such...