Yagi Masao (八木正生, Yagi Masao, November 14, 1932 – March 4, 1991) was a Japanese pianist who became devoted to American jazz very early in the wave of Japanese jazz enthusiasm.
He became a member of the Cozy Quartet in 1956 after Toshiko Akiyoshi's departure, playing alongside Sadao Watanabe.
In 1959, the twenty-six-year-old pianist formed his own group featuring several Monk tunes in their repertoire, culminating in his debut LP, Masao Yagi Plays Thelonious Monk, recorded in the summer of 1960.
"[2] Later in the 1960s he played with Charlie Mariano, Hidehiko Matsumoto, and Helen Merrill, and in the 1970s led his own ensembles.
He was well-known as a composer and arranger, and wrote copiously for film soundtracks.