Whats this cartoon/film about this bird?

I'm pretty sure you're referring to the animated film adaptation of E. B. White's classic, "Trumpet of the Swan." Though the film, if I remember correctly, differs a lot from the book, it has the same basic plot line involving swan who was born mute. I don't know if they changed his name for the film, but in the book, his name is Louis. Eventually, as the story progresses, Louis learns how to write on a slate to communicate with people, and he also learns how to play the trumpet to impress a female swan he falls in love with, since he is mute and therefore unable to produce a mating call. He also, as you said, preforms on stage, because he wants to pay back a debt to the man his father stole a trumpet from, the same trumpet that is now in his possession. And the animators did feel a need to give him yellow hair in the film. XD Hope that helps!