need help finding a movie

im looking 4 a movie that is a porkys style movie i saw when i was young...teens in the 60's - 70's raising hell...i dont remember much of it but the one part i remember was when one of the characters got infront of an audience in a suit and sunglasses and was the one armed violinist...he had one arm tucked inside his coat and when he was done playing his finger came out of his zipper and held the violin stick as if his D*** was holding it....can anyone recall this movie?