Rotating and pivoting?

[plane]

I can't remember how to rotate using the transform tool so that the top part stays still. Like something that is hanging.
Example: a chain hanging with a ball attached to the bottom. You want to top of the chain to stay still but the rest is swinging back and forth for an animation.

[plane]

Well I kept searching and looking and I think I've got it! Holding ctrl down and sliding the pivot point to the top. Persistence pays.