Music for Orchestra was conceived as a ballet for four characters or groups of characters. Initially represented by by the woodwinds, brass, percussion, and strings, respectively, they appear on the stage in starkly contrasting primary colors. Their charactersistic manners of expression are supported by the orchestra's music: the strings are almost immobile, the woodwinds begin with a quick explosion, the brass begin with a solemn chorale, and the percusiion quietly tap in the background.

The various characters interact: strings speed up, woodwind explosions take longer and longer to settle, etc. The music reaches a climax and the "percussion" characters take the center stage as the others disappear into the darkened corners.

When the lights reach onto the corners at the end of the percussion solo, the dancers' costumes are transformed into rainbow pastels, blurring the distinctions between them.The transformed characters interact with approximately reversed roles and arrive at a climactic full orchestral restatement of the brass's opening chorale, which dissolves as the lights go down..

The piece is based harmonically on the opening three brass chords. All the pitches are derived from these, more or less directly.