Eine Kleine Nachtmusik, 1st movement: Allegro
Duration of performance: c. 5 minutesDiagram of basic scheme The structure Mozart uses in the first movement is the classical sonata form. It is a small-scale symphony movement with exposition (presentation of the themes), development (elaborating the themes) and recapitulation (repeating the themes) with a coda of 6 bars. Form scheme
1st movementThe formal structure can be read easily from a diagram. 
bars 1-4The main theme behaves like a fanfare and might be regarded as a proclamation of the serenade. In the first movement the serene, unencumbered beauty of Mozart’s music becomes obvious. The first four bars of the piece consist of the simple basis of musical technique. The basic key of the work is G major; in the first two bars Mozart fragments the G-major accord G-B-D and continues with the dominant key and the dominant seventh chord D-F sharp-A-C in the following two bars.
bars 5-10The main theme is continued as an elaboration.
bars 11-17The bridge to the secondary theme is a melody of 4 bars. A slow, tense ascending second step is contrasted with several quick descending seconds.
bars 18-27The second part of the bridge has the task to modulate into D major, the dominant. The first 2 bars in G major are followed by the D major scale in the 3rd and 4th bars, finally stabilising on D major.
bars 28-35The triad D-F sharp-A forms the secondary theme which, after its presentation, is taken up in another octave by the 2nd violin.
bars 35-51The graceful theme of the closing group consists of 8 bars; the first 4 bars in piano form the "premise", followed by a "confirming" conclusion in forte.
bars 51-55The epilogue is a short melodic sequence, stressing the D major key by a frequent use of the key note C sharp.
bars 56-59The development uses simple means. At first the main theme is presented.
bars 60-72In the brief development Mozart makes free use of the closing group. It is played in C major, transposed several times, as if it were to be illustrated with the help of different keys.
bars 72-75The development is concluded by a motive that is taken up unisono by all instruments. This paves the way for the recapitulation.
bars 76-79The recapitulation repeats the exposition. All the themes occur again in the home key G major.
bars 132-137The musical material of the Coda (6 bars) is the G major chord G-B-D, which is played by the first violins in a fragmented form. The first movement of the Serenade, devised with the technique of a symphony movement, comes to a serene conclusion.
