Just a small selection of tunes for Halloween.
Dvorak's The Water Goblin
Mussorgsky's Night on Bare Mountain (via Rimsky-Korsakov)
Grieg's March of the Trolls
Schubert's The Erl King
Berlioz's March to the Scaffold
Saint-Saens' Danse Macabre
There are many, many more of course. This is just a taste! Enjoy and explore!