His cue here is the text of Browning's poem where, having "leaned out of window for fresh air," Fra Lippo Lippi hears a "sweep of lute-strings, laughs, and whifts of song" (11.
There came a hurry of feet and little feet, A sweep of lute-strings, laughs, and whifts of song,-- Flower o' the broom, Take away love, and our earth is a tomb!