CAMBRIDGE — Claudio Monteverdi’s “Vespro della Beata Vergine” of 1610 has been called his “secular contribution to sacred music.” To the five psalms, the Marian hymn “Ave maris stella,” and the Magnificat of the standard Vespers, Monteverdi added four motets to texts drawn from, among other sources, the Song of Solomon. The result is a full-blooded love song to the Virgin Mary, and Saturday evening at St. Paul Church in Harvard Square, it got a full-blooded reading from Green Mountain Project.

Named after the English translation of the composer’s name, Green Mountain Project draws its performers from the New York–based Tenet and the Boston-based Blue Heron. The group made its debut in New York with this same work in January 2010; it made its Boston-area debut a year ago at St. Paul Church with a Monteverdi “Vespers of 1640.” Blue Heron director Scott Metcalfe led from the podium when he wasn’t directing from the violin section; Tenet director Jolle Greenleaf was among the sopranos.