Final answer:
A Baroque concerto characteristic is an ensemble featuring one or more solo instruments accompanied by an orchestra.
Step-by-step explanation:
A characteristic of a Baroque concerto is typically an ensemble featuring one or more solo instruments accompanied by an orchestra. This is distinctly different from a solo concerto, which features only one solo instrument with orchestral accompaniment, or a concerto grosso, which features a group of solo instruments contrasting with the full ensemble. The Baroque concerto could include a variety of instruments as the focus, but always in the context of the larger ensemble.