The Simpsons Treehouse of Horror episodes from the first through XIII were written by multiple people and the first episode had multiple directors and music composed by Alf Clausen.
It is the first Treehouse of Horror episode. This is also the first episode to have the music composed by Alf Clausen. From "Treehouse of Horror" to "XIII", all three segments were written by different writers and in some cases there was a fourth writer that wrote the opening and wraparound segments. The original episode even had three different directors. 
