DENIS STEVENS , Professor of Music at Columbia University, New York, talks about settings of Petrarch. He compares settings of Hor che'l ciel e la terra by Tromboncino, Cipriano di Rore and Monteverdi, and introduces excerpts from settings as far removed in style and period as Giaches de Wert , Lassus. Vicentino, Schubert, Liszt and Fricker. followed by an interlude