Final answer:
Billie Holiday was a famous jazz singer, and the two men who were band leaders at the Cotton Club are Cab Calloway and Duke Ellington. Louis Armstrong, while influential, was not a band leader at the Cotton Club.
Step-by-step explanation:
One famous jazz singer was Billie Holiday. The two men who were band leaders at the Cotton Club are 1) Cab Calloway and 3) Duke Ellington. The Cotton Club was a famous venue during the Harlem Renaissance, where many prominent jazz musicians of the era performed. While Louis Armstrong was a significant figure in jazz and had a major influence on the music of that time, he is not specifically noted for being a bandleader at the Cotton Club. Armstrong worked with other blues artists such as Bessie Smith and had a major impact on the development of the genre, but it was Ellington and Calloway who were definitively tied to the Cotton Club as bandleaders.