Merrily We Roll Along is a song written by Charlie Tobias, Murray Mencher, and Eddie Cantor in 1935, and used in the Warner Bros cartoon Billboard Frolics that same year. It is best known as the theme of Warner Bros.' Merrie Melodies cartoon 'series.
The first cartoon to use the song as its title theme was 1936's Boulevardier from the Bronx. The series continued to use the tune until 1964, when both the Looney Tunes and Merrie Melodies title sequences were completely revamped following the Warner Bros. Cartoons' closure. The opening theme was now a "clunky" cover of The Merry-Go-Round Broke Down by William Lava.
Unlike the Looney Tunes theme song (The Merry-Go-Round Broke Down) this Merrie Melodies song, to date, has not been sung by any character.
The theme song is later split in half to be used as the opening and closing music respectively for the Looney Tunes CGI theatrical shorts since 2010, beginning with Coyote Falls.
In the 1970s it was adopted by WGN as the theme music to The Ray Rayner Show (Ray Rayner used Warner Brothers cartoons on his show) and in 1995 it was used as the ending theme of The Sylvester & Tweety Mysteries.
The song shares a title with the 1934 play Merrily We Roll Along by George S. Kaufman and Moss Hart, but is unrelated to it.