I remember watching this movie as a kid. But the more and more I try to think about it, nothing more comes to mind. I believe the movie was intended for children, it had many colors in it and singing, dancing, etc... but with animated characters. There were mushrooms (which I think bounced around) and were also animated. I remember them being in a cave/tunnel at one point. I remember a tornado as well. I don't remember if there are people in this... but it was a very "trippy" movie.

Can anybody help?

Fantasia?

It wasn't a Disney movie :(. When I had it, it was on VHS. I also remember it was in a forest. But that's all I can recall.

The Elmchanted forest.

You have saved me from going insane, thank you.