sentences:  Robb composed a large body of music, including two operas, symphonic and chamber music, and electronic music .His orchestral works have been played by many major orchestras in the United States and abroad under conductors, such as Hans Lange, Maurice Bonney, Maurice Abravanel, Leonard Slatkin, Gilberto Orellano, Yoshimi Takeda, Guillermo Figueroa, James Richards and Franz Vote .Robb was in his 70s when he discovered an entirely new medium for his musical compositions.