"Solitude" was written in the mid-thirties, just following Ellington's first major period of mature musical innovation as the bandleader at the Cotton Club in Harlem. The band was now more famous, touring both nationally and internationally, and recording more frequently. While this prompted Ellington to even more experimentation with varied and larger forms, he continued to crank out short, deceptively simple, and perfectly crafted tunes for the rest of his career. The conservative estimate is that Ellington wrote around two thousand individual compositions! While hundreds of these are accounted for by short three-minute instrumental pieces and pop songs, this list still includes countless concert suites, film scores, musicals, and an unfinished opera.