John Cage’s Concerto for Prepared Piano and Chamber Orchestra (1950-51) holds a unique position within the composer’s oeuvre as the first work based in part on chance-derived compositional procedures. Cage entered into such practice gradually, incrementally abandoning subjective taste and personal expression through the course of the work. Drawing from the philosophical framework provided by Cage’s "Lecture on Nothing" (1950) and "Lecture on Something" (c. 1951-52), this thesis explores the aesthetic foundations of the concerto and examines Cage’s compositional methodology throughout its three movements. Special attention is paid to the procedure underlying the first movement, whose analysis is based largely on the composer’s manuscript materials for the work.

Modest Musorgsky completed two versions of his opera Boris Godunov between 1869 and 1874, with significant changes in the second version. The second version adds a concluding lament by the fool character that serves as a warning to the people of Russia beyond the scope of the opera. The use of a fool is significant in Russian history and this connection is made between the opera and other arts of nineteenth-century Russia. These changes are, musically, rather small, but historically and socially, significant. The importance of the people as a functioning character in the opera has precedence in art and literature in Russia in the second half of the nineteenth-century and is related to the Populist movement. Most importantly, the change in endings between the two versions alters the entire meaning of the composition. This study suggests that this is a political statement on the part of the composer.

Hector Berlioz's Messe solennelle, his first publicly performed work, was important to his establishment in Paris as a composer. Although he later destroyed the Mass, he reused parts of the Resurrexit movement in three of his later works: Benvenuto Cellini (1836), the Grand messe des morts (1837), and the Te Deum (1849). This study examines the Resurrexit and its subsequent borrowings. In each instance that Berlioz borrowed from the Resurrexit, he extracted large sections and placed them in the context of later works. Each time that borrowing occurred, Berlioz constructed the surrounding music so that portions from the Resurrexit would fit stylistically and a seamlessly into the texture. In each borrowing, he left the melody unaltered, changing harmony and orchestration instead. This pattern of borrowing demonstrates that Berlioz developed his concept of melody early in his career, and that his method of self-borrowing was consistent in each subsequent use of the Resurrexit.

The Fourteen Seréstas of Heitor Villa-Lobos comprise a group of songs that expresses Villa-Lobos's compositional technique for the voice. These songs are challenging as a topic because not much historical or analytical research has been done on them. I approach the topic by providing historical background on the modinha and how it relates to the serésta. This is followed by a descriptive analysis in the order of the set, which includes musical examples, chart diagrams, and comparisons of the seréstas to other works. I hope to have contributed valuable information to the research of these songs since Villa-Lobos wrote over ninety solo vocal songs which still await analysis and discussion. This thesis is a contribution toward narrowing this gap.