Looking for a movie...
It's about a guy (Jackie chan) who is basically a Person/Dog and everytime he takes off his collar he beats the shit out of his masters enemies but he gets out of his control with the inspiration of music, but his master finds him and puts him in a Competition to the death where he wins and then goes away (again) but he finds out his master killed his parents so he fucking pwns him.
Hope that was descriptive enuff