The terms “serenade,” “divertimento,” “partita,” and “cassation” were all virtually synonymous for late 18th-century composers, describing light compositions of several short movements, designed for outdoor entertainment. “Notturno” signified only that the piece was intended for an evening’s entertainment.
Mozart’s “Serenata Notturna” is nonetheless an unusual piece. It combines a string orchestra with timpani (but without timpani’s usual companion of two trumpets) with a solo concertante string quartet whose lowest voice Mozart’s indicates as “basso,” not “violoncello” which instead appears as the lowest written voice in the orchestra. (The double bass, or “Violone,” then actually provides the true sounding bass, an octave below the cello, for both the quartet and the orchestra.) The piece hearkens back to the baroque concerto grosso, with all three movements focusing on the alternation and interchange of the solo quartet and the orchestra. The three movements themselves are unusual – a march, a minuet with trio, and a rondo – more compact than the usual five or six movements of most serenades and divertimenti. The third movement, “Rondeau,” is especially charming with its sly returns of the rondo theme, introduced in our performances (as we imagine would surely have taken place with Mozart’s own orchestra) by quasi-comical lead-ins to the principal theme.
Mozart’s manuscript indicates the piece was completed in January 1776. Given the time of year, it was probably written for an indoor entertainment of some kind. But what might that occasion have been? Is it possible that Mozart (born January 27, 1756) wrote the piece for a party celebrating his own 20th birthday? Might that explain the fact that the “Serenata Notturna” is a special, quite unique piece, among the multitude of occasional works for entertainments of various kinds he wrote throughout his life? – James Freeman