Board Thread:Lore Discussion/@comment-24383960-20140427012628/@comment-25047024-20140427085726

This doesn't have much to do with lore.

Anyways, Nerevar Rising (Morrowinds main theme), Reign of the Septims (Oblivions main theme) and Skyrims main theme are all composed by Jeremy Soul.

He seems to simply be "altering" Nerevar Rising in each newer game.