I don't think the tune IS derivative, for the reason I've stated. Notice how the similarities were obscured by the addition of notes, a change in the meter, and the going off in a new direction. This defines melody creation. I think the previous comment redefines "derivative" a bit. Composers develop and extend the musical language of melody; this does not make their works derivative. PS: Sorry if I got this thread off-topic. Those interested in such questions might want to visit my music theory page, then e-mail me if they want to comment.