The violin concerto in g minor, in the Gunnerus collection known as XM 121, is an excellent piece of music. It displays the skills of an unknown master; both harmony and counterpoint is flawless.
The two fast movements are both fugues. Who has composed violin concertos that include fugues? I can only think of Bach’s double concerto BWV 1043, and Vivaldi’s RV 565 from L’estro armonico. Please comment below if you know other examples!