Al Levy recalls playing with Fess Duncan and his El Nido Cafe Band  (Stoddard pp. 132-3).  He does not indicate a year but the Oakland Tribune of 6 June  1930 advertises Fess Duncan and his Red Hot Jazz Hounds at the El Nido Cafe.  The band in Levy’s time consisted of Chester Wells (sax), Danny Webster (trumpet), Buster Wysinger (drums), Levy (banjo) and Duncan (piano).  International Musician January 1925 Vol 23 Issue 7 includes Fess Duncan among the new members of Local No. 648 Oakland and in March 1928 reports his reinstatement in the same Local.  In 1927 he was playing with Al Stewart and his five-piece (six-piece with the addition of Barnette) Brown Skinned Jassopators at The Green Lantern near Del Monte - (Stewart [sax], Duncan [piano], Harry Barker [trumpet], Cus Deluce [trombone], Les Robinson [drums], Ed Barnette [sax and clarinet]).  They are said to have been “Winners of the California Colored Jazz band Contest, San Francisco, California, February 7.” (Californian August 31 1927 and September 17,1927).  Duncan and his orchestra broadcast on KRE in May 1930.
He was probably Chester W. Duncan, born in Texas c. 1901-3.  He moved to the Bay Area in 1924.  Voter registration lists show him in the Bay Area as a musician in 1926 and 1930 as does the Oakland City Directory for 1926 and the 1930 Census.  In 1936 he was listed in the voters’ register for Los Angeles.  I can find nothing of his life after that.