The Divertimento No. 15 in B-flat major, K. 287, is a divertimento for two horns and strings by Wolfgang Amadeus Mozart. He composed the work in six movements in 1777 for the name day of Countess Maria Antonia Lodron. It is also known as the Lodronische Nachtmusik Nr. 2.

Mozart composed the divertimento in 1777 for the name day of Countess Maria Antonia Lodron, a family friend and member of the Salzburg aristocracy.^[1] It was first performed on 13 June 1777 at an informal outdoor party.^[2]

This divertimento is scored for two horns in B-flat and strings.

The divertimento is structured in six movements:

1. Allegro (in B-flat major and in sonata form)
2. Tema con variazioni (Andante) (theme and 6 variations, where the theme and all the variations are in F major)
3. Menuetto – Trio (in B-flat major and in ternary form, trio in G minor)
4. Adagio (in E-flat major and in sonata form)
5. Menuetto – Trio (in B-flat major and in ternary form, trio in E-flat major)
6. Andante – Allegro molto (in B-flat major, beginning with an introductory instrumental recitative, and in sonata rondo form)

In 1952 George Balanchine choreographed for his company New York City Ballet a piece titled Caracole to this music. A few years later, he restaged it for a celebration of Mozart's bicentenary with some changes in score, choreography, costumes and set design as Divertimento No. 15. The ballet was premiered on 31 May 1956 at the American Shakespeare Theatre, Stratford, Connecticut.

•  Divertimento in B: Score and critical report (in German) in the Neue Mozart-Ausgabe
• Divertimento No. 15 in B-flat major, K. 287: Scores at the International Music Score Library Project