Minoru Miki's first two marimba compositions, Time for Marimba (1968) and Concerto for Marimba and Orchestra (1969) were composed at a revolutionary time-period for the marimba. Due to unique and innovative compositional techniques, Miki helped establish the marimba as a true concert instrument capable of performing music of the highest quality. As a pioneer in composing for marimba literature, Miki was able to capture the true essence of the marimba; a timeless quality that has helped Time for Marimba remain a part of the standard solo repertoire for the past forty years. The purpose of this study is to analyze and compare Minoru Miki's compositions, Time for Marimba and Concerto for Marimba and Orchestra. Composed within a year of each other, these works possess similar compositional techniques, and rhythmic and thematic relationships. This thesis includes a formal analysis and detailed comparisons of compositional techniques used in both works. Performance considerations, a brief biographical sketch of Miki and historical significance of Time for Marimba and Concerto for Marimba and Orchestra are also included.