It was written, together with the Piano Trio, while Piston was on a Guggenheim Fellowship.
[1] The quartet is in three movements: The restlessly chromatic Lento introduction to the first movement is built on a three-note motive, A–C–D♭, that is found also in a number of the composer's other works.
[2] The boisterous main allegro portion of the movement is in A minor and sonata-allegro form.
The slow movement is based on the motive from the Lento introduction of the first, and is in a chromatically inflected C major.
These tonalities contrast sharply with the equally wavering A minor and C major tonalities of the movement as a whole, which remain undecided until an A minor cadence at the end of the coda, followed immediately by a surprising Picardy third A-major triad.