Special fields: theory and performance of Medieval and Renaissance music, Medieval studies. Articles on Gregorian chant, Troubadours, Medieval Performance, Machaut, Dufay, Lasso, Dante, and English cathedrals.
Workshops in Gregorian chant and Renaissance polyphony.
Joint editor, Leonard Ratner Festschrift.
Woodrow Wilson Fellow, 1973; NEH-Newberry grant, 1976; Mellon Junior Faculty Grant, 1978; NEH Lecturer, 1986-87, 1989-90; Chairman, Western Culture Program, 1984-85.