This thesis provides evidence that a particular "topos" from the high Baroque's exalted style, the so-called chaconne bass, made a profound impact on a considerable body of Mozart's compositions from the last ten years of his life in Vienna. After identifying the topos in the first chapter, a detailed study in chapter two shows how Mozart's faith in the extraordinary emotional power carried by this topos was enough for him to work it into all of the completed keyboard fantasias. Chapter three illustrates that an understanding of the chaconne bass and its unmistakable association with the fantasia style can shed new light on three of Mozart's most enigmatic compositions from his final period, K. 465, K. 491, and K. 527.

Dominick Argento (b. 1927) occupies an important position among American composers. This thesis discusses his 1980 choral work Peter Quince at the Clavier: Sonatina for Mixed Chorus and Piano Concertante. On the surface, the choral and piano parts of this four movement work often sound dissimilar. To create unity within this composition, Argento utilizes a small number of generative elements that govern the pitch, intervallic, and rhythmic dimensions of the composition. This thesis also discusses the relationship between the music and the text, a poem by Wallace Stevens (1879-1955).