Some of Harris's compositions, especially, as indicated earlier, those in the chamber media, are predominantly polyphonic. The early music, while strongly indebted to Baroque practices in this respect, nonetheless sometimes seems contrived, with lines coalescing to produce unconvincing harmonic results. In his mature idiom, on the other hand, the counterpoint emerges from a clearer harmonic background (which, in fact, is sometimes actually present as an accompaniment);- in fact, Harris defined counterpoint as "the passing of melodic lines through a harmonic texture/' However, that he was not a natural contrapuntist is revealed by his sometimes succumbing to the use of bland arpeggiated designs growing out of the underlying harmonies instead of providing musically distinctive lines and by occasionally failing to create a sense of true rhythmic independence among the parts. In addition, the integrity of the individual lines in his orchestral polyphony is sometimes dissipated through a tendency to allow a line to degenerate into a series of repetitive motivic designs, which frequently take on an ornamental character.
Harris's orchestration is clear, to the point of strident leanness in his early scores. His instrumentation is relatively conventional, although with a few individual touches: in some works from the 1940s on, he employs saxophones and the baritone horn, as well as a kind of "gamelan" consisting of piano, harp, chimes, and vibraphone that provides a bell-like polychordal punctuation.
He preferred to score in discrete choirs, using materials taken from a storehouse of idiomatic motives, figuration, etc. he had developed over the years. There is relatively little inter-choir doubling except in the occasional tuttis, which serve chiefly to mark important structural points. Harris treated the strings in an especially flexible manner by according them extensive melodic and accompanimental functions and generally having them form a complete harmonic texture. Also, the aforementioned increasing use of divisi during the 1940s and 50s imparts a lushness to his orchestral sound that contrasts sharply with the character of the earlier music. In his brass writing, Harris often liked to play off what he called the "sharp-tone" instruments (trumpets, trombones) against the "round-tone ones (French horns, baritone horn, tuba). He was fond of horn lines in unison and 3rds and, from the 1940s on, frequently favored the Chalumeaux register of the clarinet, a group of which formed, along with the bassoons and, occasionally, the saxophones, a resonant harmonic foundation.
