Movement 1: Allegro Movement 2: Larghetto Movement 3: Menuetto:
Moderato Movement 4: Allegro assai The explanation seems to lie
in the special terms of Frederick William’s commission. The
Prussian king was a keen amateur cellist, and collected chamber
music with prominent cello parts. In 1786, the year of his
accession, he obtained quartets of this sort from Pleyel, and
engaged Boccherini—who had developed the string quintet with two
cellos—as his chamber composer. The next year Frederick William
commissioned a set of quartets from Haydn, his Opus 50. Haydn,
as we might expect, did not respond simply by giving the cello
concerto-like passages, for that would have fatally loosened his
spare, concentrated musical architecture. Instead, he brought
the cello into the musical argument by using the sort of
motivic, semi-contrapuntal writing that he had just developed
for his ‘Seven Last Words’; he made its quartet version about
the time he began Opus 50. By 1789, however, Mozart had taken
what he needed from Haydn’