For the six concertos that make up the second part of the Op. 4, Locatelli prescribed eight parts: Violino Primo, Secondo, Alto, è Violoncello, Soli. Violino Primo, Secondo, Alto, è Basso, Ripieni. The use of such forces immediately reminds one of the Corellian concerto grosso, to which Locatelli contributed also in his Op. 1, 7 and 9. But though the instrumentation used in this set seems to feature a clear opposition between the concertino (with solo parts) and the ripieno (with parts that c...