Conversation so far:
What important event happened in Duke Ellington's early post years?
In 1951, Duke Ellington suffered a loss of personnel: Sonny Greer, Lawrence Brown and, most importantly, Johnny Hodges left to pursue other ventures, although only Greer was a permanent departee.

Question: Why was he forced to disband?
Self-contained rewrite: Why was Duke Ellington forced to disband?