The Cotton Club had tried to get Joe Oliver, who had been the king in Chicago and not used to the kind of money the Cotton Club had. Joe said no. So the Washingtonians moved in, and presently they were Duke Ellington and his band. Duke stayed at the Cotton Club, building his band and the Club's fame, until he moved out in 1931. By then they knew about him in Europe, so he booked his band for a tour of Europe.
Nothing is ever so easy as that, though.
Duke had got married when he was very young and now has a son about voting age, and a quiet home with books around and stuff. While they were living, he was more devoted to his parents than most sons. But a musician, in the main sense, does not live his life as most people. You can't get away from it, music is where he lives and where you will find him. As it was taking shape between 1927 and 1931, Duke Ellington's music was of a special kind.