Watch full movie online. Based on the classic tale of the Pied Piper, this Rock-Opera themed cartoon tells the tale of the 1960s small suburban town of Hamlin, which has been infested with rats. Sly, a Jimi-Hendrix styled guitarist, is hired to take care of the rats with his musical abilities, and is promised a Harley Davidson from the mayor as payment. When he gets cheated out of his payment, he then uses his music to lead the kids to a mountain.