東京都交響楽団
In 1956, Watanabe founded the Japan Philharmonic Orchestra and continued as its resident conductor until 1968. In 1970, he became music director of the Kyoto Symphony Orchestra, and remained so until 1972. From 1972 to 1978, he was the music director of the Tokyo Metropolitan Symphony Orchestra. In 1978, he once again became resident conductor of the newly reformed Japan Philharmonic Orchestra, with whom he stayed until 1983. In 1988, he became the music director of the Hiroshima Symphony Orchestra, and remained there until 1990. He was also a professor of conducting at the Tokyo University of the Arts from 1962 to 1967 .