 The poem consists of fifteen rhymed tercets; its prevailing meter is trochaic octameter catalectic.It is not known whether Browning was thinking of any one piece by Galuppi; in Galuppi's time, the terms "toccata" and "sonata" were less clearly differentiated than they later became, and were used interchangeably.A number of Galuppi's sonatas have been suggested as Browning's inspiration, but as Charles van den Borren wrote in "The Musical Times", "every poet has the right to evade the prosaic minutiae of fact", and it is impossible to state with confidence that one Galuppi piece has more claim than another to be the inspiration for the poem.