D Minor.
But of course.
BTW, what kind of name for a song is ‘Toccata & Fugue’?
Who the hell would use that for a name?
Why do I feel rude when pronouncing ‘fugue’?
Shamelessly link-whored from a Texan monk.
UPDATE
I don’t know what it is, maybe you musos can sort it out, but that sounds eerily similar to this.