Early Life and Musical Beginnings

Born in Tsuruoka City, Yamagata Prefecture, Sato temporarily moved to Oha in North Sakhalin and Setagaya in Tokyo, but evacuated during the war. From the second grade of elementary school until high school, he lived in his hometown of Tsuruoka City. Although his home had a violin and a piano, which his father enjoyed, it was the latter that captivated Sato. His music teacher, Nao Mitsui (who passed away in 2017 at the age of 103), whom he met during junior high school, was known as "the mother of choral music in Tsuruoka" for establishing the Tsuruoka Saturday Mixed Chorus, and had a profound influence on Sato.

He began composing self-taught around this time, but it was his failure in a song composition competition co-sponsored by Mainichi Shimbun and “Concert f” (Miho Nagato, Taneko Seki, Yoshiko Sato, Fumiko Shike) in 1956, while he was majoring in electrical engineering at Keio University's Faculty of Engineering, that prompted him to seriously study composition. Through an introduction from tenor singer Fumitoshi Hirama (1900–1989), an acquaintance, he studied under composer Yasuji Kiyose (1900–1981). Kiyose was known for a style that incorporated Japanese-style melodies and rhythms while referencing Fauré, Debussy, Ravel, Mussorgsky, and Bartók, and Sato would also develop his compositions under this influence (in an article titled "Yasuji Kiyose's Musical Language" published in the October 1972 issue of the magazine Ensemble No. 72, Sato provides a detailed commentary on his teacher's works).

Development of Compositional Style

In his early period, he primarily composed works for piano, and his Three Chapters for Piano (1959) was selected for the 28th Japan Music Competition's Composition Division, Part 2 (Chamber Music) (incidentally, the first prize in the piano division that year went to Hiroko Nakamura). Subsequently, he gradually began to compose for various ensembles, including chamber music, songs, choral works, and orchestral pieces. From 1967 onwards, he started writing works for traditional Japanese instruments. Among these, Divertimento (1969) is one of his representative works, becoming a standard repertoire piece for Japanese traditional instrument ensembles. Entering the 1970s, a significant change began to appear in his compositional style. As evident in works such as Sketches from a Snow Country (1973) and Piano Watercolor Album (1977/79/86), he began to employ previously unseen elements such as dense dissonances, tone clusters, rhythms lacking a sense of meter, and indeterminate notation. This was likely because he began to explore composers whom his teacher Kiyose had not actively incorporated, such as Stravinsky (especially his Divertimento for Four Hands from 1980) and Messiaen (similarly, Birds from 1992).

Dual Artistic Paths: Avant-Garde and Children's Music

However, even when compositional periods overlapped, such new tendencies rarely appeared in his works for children. Although Sato had been involved in creating teaching materials and training instructors for Kawai Music School since the 1960s, from the late 1970s onwards, he successively composed and published piano collections for children, including Children Play (1978), Little Palette (1979), and Piano Graffiti (1984).

These two seemingly contradictory tendencies, however, share a common thread: the expression of color in music. While Messiaen, known for his synesthesia, is famous for his vivid, intensely colorful expressions, Piano Watercolor Album, as its title suggests, is characterized by its pale color expressions, which constitute Sato's unique individuality.

Later Career and Contributions

Until his sudden death in 2002, he held important positions such as judge for the Japan Music Competition's Composition Division, chairman of the Japan Society for Contemporary Music, and head of the Music Research Department at Kawai Music Planning. He also dedicated efforts to training performers in the field of Japanese traditional music at institutions such as the NHK Hōgaku Gakuno-sha Ikuseikai (NHK Japanese Traditional Music Performers Training Program) and Tokyo University of the Arts.