The Duke Ellington Reader, edited by Mark Tucker, is treasure-trove of information on Ellington, culled from a variety of sources. A transcription of a 1962 interview conducted by Canadian broadcaster Jack Cullen reveals the background of many of Duke’s compositions. “I Let a Song...” was written during one of the Ellington band’s road trips, when the band was staying in a hotel in Memphis.
Upon his return to New York, Ellington asked lyricist Henry Nemo to write lyrics for the song with the intention of including it in the Cotton Club Parade of 1938. At that point, the publicist for Irving Mills, Ellington’s agent, picks up the story, explaining that Ellington had composed 12 numbers for the show, but, because he was superstitious, Ellington’s 13th composition, “I Let a Song...,” was not included. Another source, John Edward Haase’s Beyond Category: The Life and Genius of Duke Ellington, states that it was Mills, not Ellington, who pulled the number from the Cotton Club Parade.
I let a song go out of my heart It was the sweetest melody I know I lost heaven 'Cause you were the song
Since you and I had drifted apart Life doesn't mean a thing to me Please come back sweet music I know I was wrong
Am I too late To make amends You know that we were meant to be More than just friends, just friends
I let a song go out of my heart Believe me darling when I say I won't know sweet music Until you return someday