From allmusic.com :
Fred Guy spent most of his playing career with the Duke Ellington Orchestra. He grew up in New York City. Guy worked with Joseph C. Smith’s Orchestra and then led his own group. However after joining Duke Ellington’s Washingtonians in the spring of 1925 (replacing the group’s former leader Elmer Snowden who left after a money dispute), Guy was with Ellington for the next 24 years. He played banjo up until the early 1930’s and his rhythmic and percussive style was an asset to the early band. However after switching to guitar, Guy tended to be inaudible and (since he never soloed) an increasingly minor force in the music. When he departed from Ellington in 1949, there was no need to replace him. Fred Guy (who never led his own record date) was never again a fulltime musician, working as a manager of a ballroom in Chicago. He was long forgotten (except by jazz historians) by the time he passed away in 1971. ~ Scott Yanow, All Music Guide
Duke Ellington And His Orchestra – The Brunswick Era Vol I 1926-29 features Fred on Banjo.
Here is a nice podcast episode from THE HISTORY ANEW PODCAST Presented by Antony Pepper that features some Duke Ellington tunes with Fred on the banjo.