The Essay for Orchestra combines three contemporary styles of melodic writing into sonata form. The exposition contains three themes. The first theme is a twelve-tone row. Unlike the usual approach to serial writing, the row is used in its original form throughout the piece and is developed by rhythmic alterations. The theme never occurs in its inversion or retrograde. The second theme of the exposition illustrates a chromatic type of melody. The third theme in the exposition is constructed of ascending and descending leaps of perfect fourths interspersed with leaps of thirds and short scale lines. The constant use of this theme throughout the development section provides the composition with a melodic unity.