"SINFONIETTA" is constructed on a free usage of the traditional Sonata-form. It has an introduction; an Exposition, with two principal themes; a Development, in which both principal themes are used; and a Recapitulation, in which both principal themes are combined.

The form of the movement is as follows: Slow introduction; forceful theme "A"; lyrical theme "B"; bridge between second theme and development section; development of theme "B"; another bridge developed from a fragment introduced immediately preceding the bridge which is used for a climax before theme "C" is introduced and developed. with the end of the development of theme "C", the development section ends, and thus begins the recapitulation of themes "B" and "A" in that order with little variation in either from that of the exposition. Theme "C", since it played such an integral part in the development section, is not brought back in the recapitulation.