From Video Game Music Preservation Foundation Wiki
Vampire Killer is the music that plays in several levels of Dracula's castle, but most notable the first level.
The song is track 2 in the NSF file. The title comes from an official album.
- Konami Music Masterpiece Collection - Disc 7, track 3. Titled "BGM #1"
- Konami Game Music: Classic Castlevania - Track 3. Titled "Vampire Killer (Breaking Into the Castle BGM)"