Some classical pieces that I think apply.
[youtube]http://www.youtube.com/watch?v=_SXJDAIDNoQ[/youtube]
[youtube]http://www.youtube.com/watch?v=Js3y6ouy1rQ[/youtube]
This is pretty quiet but it still has a lot of tension so it's "heavy" in a way.
[youtube]http://www.youtube.com/watch?v=zuh3WyfVL2M[/youtube]