This manuscript is a study of four piano works of Scarlatti, Mozart, and Schumann, which I recorded as part of my D.M.A final project. The works are Scarlatti Sonatas, K. 141 in D Minor and K. 380 in E Major; Mozart Piano Sonata, K. 576 in D Major, and Schumann Carnaval, Op. 9. These works were chosen because each presents technical innovations in keyboard playing for its time and instrument. Scarlatti’s output for the solo keyboard is comprised almost entirely of sonatas. Although he did not collect the sonatas within the framework of the Baroque keyboard suite, each of his sonatas has its own distinctive character, and that character is sometimes marked by virtuosity and innovations in keyboard technique. His sonatas K. 141 in D Minor and K. 380 in E Major represent technical innovations using guitar technique, rapid repeated notes, imitating horn calls and Spanish dance rhythms. Mozart’s last Piano Sonata, K. 576 in D Major, is one of his most difficult works for keyboard and occupies a unique place in his repertoire. Before K. 576, Mozart’s keyboard sonatas primarily utilized homophonic textures, but this last sonata is largely contrapuntal, and also among his most virtuosic. Schumann’s Carnaval, Op. 9, is a collection of character pieces, each identified by its own title. Schumann presented the different personalities drawn from his dual fantasy characters, his colleagues and friends, and the Italian Commedia dell’arte figures. The work is technically demanding, and Schumann strives to fully realize the expressive range of the piano. He expands keyboard techniques by writing intervals and chords that require a much wider stretch of the hand, using a wider range of the keyboard, and introducing new pedal techniques.