He was striking a few preliminary chords and indulging in an extemporised prelude.

A pause, and then he commenced Purcell's song.
The plaintive melody with its well balanced phrasing took Lavinia's fancy, and absorbed in the music she forgot her audience.

She saw how the words were wedded to the notes and watched where the trills and graces came in.

Pepusch played the air right through; waited a minute or so and recommenced.
Lavinia began.

She sang like one inspired.