In the creative activities of composer Minao Shibata (1916-1996), who left behind many compositions and other writings from the pre-World War 2 era and into the 1990s, a group of choral works called “theater pieces” occupies an important position. In many cases, theater pieces refer not only to ordinary performances, but also to works that are performed with consideration for the performer’s physical movements and the spatial nature of the venue, and actual conditions will vary depending on the composer and the work. Shibata’s theater pieces are mostly choral works, and they are characterized by the use of traditional Japanese materials as well as physical and visual performances. Shibata left behind about 20 theater pieces in a variety of styles, indicating that he was exploring various forms of expression. His transition can be categorized into three periods: (1) a period when he focused on Japanese folk music, (2) a period when he focused on music, literature, and academia from various part of the world, and (3) a period when he focused on regions throughout Japan. In other words, he started with traditional Japanese music, broadened his perspective to include overseas influences, but then returned his attention to Japan again. Shibata referred to the group of works that arose from his rediscovered interest in Japan as a “New Series of Theater Pieces”. In this paper, the writer analyzes the structure of five works from the “New Series of Theater Pieces”, and examines the meaning behind the transition that took place in period (3) above. The results of this analysis show that rather than simply returning to Japanese material, Shibata found a good balance that included his previous experience and styles.