This piece of Modest Moussorgsky was published posthumously by Nikolai Rimsky-Korsakov, and later made famous by a version performed in Disney's Fantasia.

It's one of the longest pieces I've arranged, and I'm pleased to say that this time, Musescore 4 played and rendered it acceptably as written.

While I realize the version in Fantasia is not the same (I haven't re-listened to it yet), I don't recall many of the themes that were found in this version.