In 1931, producer Leon Schlesinger had already produced one cartoon in the Looney Tunes series, and its success prompted him to try to sell a sister series to Warner Bros. His selling point was that the new cartoons would feature music from the soundtracks of Warner Bros. films and would thus serve as advertisements for Warner Bros. recordings. The studio agreed, and Schlesinger dubbed the series Merrie Melodies.
Walt Disney Studios had already scored with their Silly Symphonies. Since cartoon production usually began with a soundtrack, animating a piece of music made it easier to devise plot elements and even characters.
The Merrie Melodies series was taken on by Rudy Ising, one of the two animators who had worked on the original Looney Tunes short. Ising attempted to introduce new characters in his Merrie Melodies films, such as "Piggy" and "Foxy", but Foxy was so derivative of Mickey Mouse that he was dropped, possibly at Disney's urging. The Merrie Melodies shorts became largely plotless musicals or romances without any recurring characters and continued in this vein even after Ising left the studio in 1933.
In 1934, Schlesinger produced his first color cartoons, the Merrie Melodies shorts "Honeymoon Hotel" and "Beauty and the Beast" which were produced in Cinecolor (Disney had exclusive rights to the richer Technicolor). Their success convinced Schlesinger to produce all future Merrie Melodies shorts in color as well. Looney Tunes continued in black and white until 1943.
Contractually, Merrie Melodies cartoons were obligated to include at least one full chorus from a Warner Bros. song. Warner Bros. requested that these songs be performed by name bands whenever possible, but this lasted only through the first few shorts. The policy annoyed the animators of Merrie Melodies, since the songs often interrupted the cartoons' momentum and pacing.
In the late 1930s, the animators were released from this obligation, and the Merrie Melodies shorts came to resemble more closely the black-and-white Looney Tunes series. In 1943, Schlesinger began producing Looney Tunes in color as well, and the two series became virtually indistinguishable except by their theme music and opening titles.
Warner Bros. continued their fondness for paying themselves for music performance rights, however, as shown by the frequent repetition of "The Merrie Go Round Broke Down" and "Singing in the Bathtub", and the music of Carl Stalling and Raymond Scott, particularly "Powerhouse".