At the outset, I should perhaps explain why I'm going to play the illustrations to this talk on the piano rather than on a harpsichord. In the first place, I only play the harpsichord as an amateur, and would feel abashed to display my shortcomings before an audience containing many eminent professionals. And secondly, since harpsichords are still comparatively few and far between, I'm anxious to suggest that students and performers can give great pleasure to themselves, and to others, by playing these works understandingly on whatever keyboard instrument happens to be available.