It was a fascinating class that beautifully demonstrated how having these first millennium manuscripts available to everyone, not just specialists, can enhance both understanding and performance of the chant, as a natural outgrowth of the work began by the Solesmes monastery.
It was particularly gratifying to see this level of exploration because it represents a continuation of a tradition of publishing within the CMAA. Under the editorship of Msgr. Schuler, Sacred Music published fully six large studies in the 1980s on the topic of semiology (including by Fr. Kelly and Dom Cardine). Until very recently, these were the only in-print resources in English on this topic.
Dr. Schaeffer also visited other chant groups to help them see some of the shadings behind the chants they would sing at Mass that day.
Another student was Fr. Jonathan Gaspar, director of the office of worship for the Boston Archdiocese.