Serenade No. 9 in D major, K. 320, ‘Posthorn’

Program notes

About the Work

The University of Salzburg closed its academic year each summer with graduation ceremonies, and part of the tradition was a Finalmusik, a serenade for orchestra. Wolfgang Amadeus Mozart, then twenty-three and employed at the Salzburg court, wrote the one for 1779. His manuscript is dated 3 August of that year.

A serenade was occasional music, and it was built more loosely than a symphony. Mozart’s has seven movements. A substantial opening movement and a quick finale frame the whole. Between them come two minuets, a slow movement and, in the middle of the work, two movements that amount to a small concerto for the woodwind section.

The orchestra is big for the purpose: pairs of flutes, oboes, bassoons, horns and trumpets, with timpani and strings, plus two visitors who appear only in the second minuet. One is a piccolo. The other is a posthorn, the valveless horn that signalled the arrival and departure of the mail coach. It plays in a single trio and has given the whole work its nickname. It is tempting to hear it as a wave to the students who were about to leave town for the summer, though nothing from Mozart’s hand says so.

A complete performance takes about three quarters of an hour.

What to Listen For

I. Adagio maestoso. Allegro con spirito. A few bars of slow, ceremonial introduction, then a quick, energetic Allegro.

II. Minuetto. The first of the two minuets, sturdy and formal.

III. Concertante: Andante grazioso. The strings step back and the principal flutes, oboes and bassoons come forward as soloists, in G major, over a light accompaniment that includes plucked strings. Near the end the wind players have a cadenza to themselves.

IV. Rondeau: Allegro ma non troppo. The concertante idea continues, with the tune carried mostly by a solo flute and a solo oboe.

V. Andantino. The surprise of the work: a slow movement in D minor, beginning low in the violins over murmuring basses. For a few minutes the party music is set aside for something inward and troubled.

VI. Minuetto, with two Trios. The mood lifts again. The first trio is a solo for piccolo over the strings. The second brings the posthorn, with its handful of open-air notes.

VII. Finale: Presto. A fast, brilliant close in D major for the full orchestra.