As traditional methods and goals of composition were challenged in the twentieth century, American composers played a critical role in the development of classical piano music. This dissertation focuses on the diversity of innovation that led to the evolution of classical music written for the piano. These innovations generally fall into two categories: musical construction and extended techniques of sound production. Charles Ives and George Gershwin successfully merged elements of American popular culture with classical music. Ives included American hymn tunes in his First Piano Sonata and Gershwin's Rhapsody in Blue was one of the earliest attempts to fuse jazz and classical music. Similarly, the piano rags of William Bolcom paved the way for the acceptance of ragtime in the concert hall. In his Piano Sonata, Aaron Copland showcases his motivic method of composition. Each movement is largely composed of small motives that expand

and create a larger shape. Leon Kirchner's Piano Sonata No. 3 is an example of idiomatic piano writing in the 21st century, recalling compositions of the late 19th century. Initiating the expansion of piano sonorities were American composers Henry Cowell and John Cage, who created what are now known as "extended techniques." Aeolian Harp was Cowell's first piece written exclusively for "string piano," a term which describes his technique of strumming and plucking the strings. Cowell's invention paved the way for the "prepared piano," an invention by John Cage that transforms the tonal range of the instrument. George Crumb's monumental two-volume work for amplified piano, Makrokosmos I & II, further expands the possibilities ofthe instrument to create an unprecedented sound world. Frederic Rzewski's set of folk-inspired pieces, North American Ballads, fuses American history, American folk music, and extended techniques with classical composition. This dissertation comprises three piano recitals that were performed from

2011 to 2013 in Gildenhorn Recital Hall ofthe Clarice Smith Performing Arts Center of the University ofMaryland. The recordings are documented on compact discs that are housed within the University of Maryland Library System.