 An extant theatre almanac from 1782, from the Burgtheater in Vienna, suggests that, for the theatre, there were 35 members of the orchestra, e.g., six first and six second violins; four violas; three cellos; three basses; pairs of flutes, clarinets, oboes, and bassoons; horns; and trumpets, with a timpanist.All of Mozart's mature concertos were concertos for the piano and not the harpsichord.His earliest efforts from the mid-1760s were presumably for the harpsichord, but Broder showed in 1941 that Mozart himself did not use the harpsichord for any concerto from No.