The Smurfs and the Magic Flute

The Smurfs and the Magic Flute French La Flte six schtroumpfs , lit. The Flute of Six Smurfs is a 1976 Belgian animated film starring the Smurfs, directed by their creator, Peyo. Though the film premiered in 1976 in Belgium, and 1979 in the United Kingdom, an English language version was not released in the United States until 1983, in the wake of the characters newfound popularity. The American version of the movie premiered alongside the Inspector Gadget episode, Quimby Exchange.

This story is set at a castle during the Middle Ages. One day a merchant brings musical instruments to sell to Peewit, the court jester, but because Peewit is such a terrible musician the King throws the merchant out before Peewit arrives. However he has left behind a flute that only has six holes. The King throws it into the fireplace in his room, which starts to emit green smoke. When the fire is put out, Peewit retrieves the flute from the ashes unharmed. He cleans it and starts playing it for the whole castle realizing that it causes everyone to dance when it is played.That night a man named Matthew McCreep learns from the merchant that the same flute he had been looking for is at the castle. He heads over to the castle and steals the flute from Peewit. The king sends Peewit and the young knight Johan out to catch McCreep who uses the flute to rob people of their money. However McCreep uses the flute to stop them. Johan and Peewit then go to the house of Homnibus the wizard. Using a spell called Hypnokenesis, the wizard sends Johan and Peewit to Smurfland where the magic flute was built. ........

Source: Wikipedia