Prologue:
https://www.youtube.com/watch?v=0WANyvWUtwY
Undead Burg:
https://www.youtube.com/watch?v=eMwTXfzQQyA
Undead Parish:
https://www.youtube.com/watch?v=H53nwyhh_O4
Lower Undead Burg:
https://www.youtube.com/watch?v=oYx0xtIshqA
The Depths:
https://www.youtube.com/watch?v=HAGfZEiM8zQ