A twentieth-century Earth song that Voyager's Doctor sings with Seven of Nine during her lessons in social behaviour, revealing that the former drone has a fine singing voice.
You Are My Sunshine is an old Earth popular song. It features in the Voyager episode Someone to Watch Over Me, set in 2375, in which the Doctor undertakes to teach Seven of Nine the customs of human courtship.
One of his lessons concerns sharing a pastime, and he chooses singing. Seven joins him in a duet of the song and produces a clear, accurate voice that takes the Doctor aback.
The scene marks the point at which the teacher begins to fall for his pupil. He never tells her so, and the episode closes with him alone at the piano singing the standard that gives it its title.