"Yeah, jamboree music! Wait, is that blood!?"
Yeah, the lighthearted music didn't really fit with the giant-skeleton-with-a-pumpkin-for-a-head chase. Scary chase scene could have actually been scary with some scary music. The harmonica seems to be a recurring musical element, and while I don't mind harmonica, it does seem a bit repetitive.
The whole thing isn't off to an exciting start really, and the skeleton chase would have turned that around if not for the poor choice in bgm(just the one, the harmonica stuff was ok).