Which composer wrote the orchestral work Night on Bald Mountain?

Modest Mussorgsky wrote the orchestral work Night on Bald Mountain.

Mussorgsky developed Night on Bald Mountain from 1866 onward, using the image of a witches’ gathering on a mountain. The piece exists in several versions, including an original orchestral version and a later arrangement by Nikolai Rimsky-Korsakov. The Rimsky-Korsakov edition became the version most often performed in concert.

Mussorgsky’s original was not performed publicly during his lifetime. Rimsky-Korsakov substantially revised and orchestrated the music, and that version was first performed in Saint Petersburg in 1886, five years after Mussorgsky’s death.

The work became widely known through its appearance in Walt Disney’s 1940 animated film Fantasia, where it accompanies a supernatural sequence featuring Chernabog. That association sometimes leads listeners to credit the piece to Rimsky-Korsakov, but the underlying composition is Mussorgsky’s.