Opal D. Cooper was a singer, pianist and actor who experienced marginal success in the United States and parts of Europe during the 1920s and 1930s. Bom in Cromwell, Kentucky (noted in some of his records as Cromwell, Ohio), one of Cooper first appearances was in the musical comedy Darkydom (book by Henry Troy, lyrics by Jesse Shipp, and music by Will Marion Cook) at the Lafayette Theater in New York City in 1915. The play also featured the comedy duo Miller and Lyles. Two years later, Cooper appealed as Madison Sparrow in the play The Rider of Dreams, written by Ridgely Torrence. One newspaper reported that Cooper was so nervous opening night that he gave a "miserable" performance. In later shows, his performance improved, and was generally well received as indicated by critic Louis Sherman who wrote that. Cooper as the Rider of Dreams, a mixture of poet, savage and vagabond, brought down the house time and time again". Often described by critics as "robust", "large", or "a bronze giant", Cooper continued to make a name for himself by appearing at church benefits and as a featured guest in minstrel variety shows in the New York area.
In 1918, Cooper enlisted in the United States Army, and was assigned to the 807 Pioneer International Band, which performed overseas. He rose to the rank of sergeant, and following his discharge in 1919 he remained in Europe and joined the American Legion in Paris.
From 1920 to 1939, 'Ole' Cooper, as he was sometimes known, worked as a singer and musician in various theaters and restaurants in Paris, other parts of Europe, and in India. As a result of the lack of work due to the onset of World War II, he returned to the United States and resumed his career performing in clubs in New York City and in Hartsdale, New York.
Cooper performed with a number of bands during his career. Before joining the service, he was a member of the James Reese Europe's Octette of Singers and Players, managed by Noble Sissle. Other bands included the Five Red Devils and the International Four which featured Sammy Richardson, Freddy Brown and Wilbur White. He also performed in a group with composer DeKoven Thompson and singer Creighton Thompson, two cast members of the aforementioned Darkydom. Throughout his career, Cooper appeared alongside prominent singers and musicians of their day, among them Abbie Mitchell, Ella Fitzgerald, W. C. Handy, C. Luckeyth "Lucky" Roberts, Elizabeth Welch and Sidney Easton.
In 1949, Cooper married Cora Outten. In the late 1960s, the couple lived in the Bronx and Cooper worked as a licensed taxi driver, an occupation he held until his death in 1974.