This thesis consists of five parts: First, introduction and historical review of “piano duet” and “piano duo” is provided. Second, practical approach on learning piano four-hand music and its pedagogical value is explored. Third, analysis and discussion of technical ensemble difficulty, focusing on Debussy’s Petite Suite is provided. Fourth, analysis and discussion of technical ensemble difficulty, focusing on Milhaud’s Scaramouche is provided. Fifth, conclusion.

　　The attachment is the DVD of live performance of the researcher’s “Performance Recital.”