Question

Unlike the concerto, where the soloist is accompanied by an orchestra, a __________ uses a piano to accompany the soloist.

Answer 1

Grosso cannot be the answer since Grosso is a form of concerto still that transitions to a full orchestra. Madrigal as well is a  group of singers singing songs in the Rennaissance age. Cantata is accompanied by a choir which means the answer is Sonata which is accompanied usually by a pianist.