UPDATE: It was just an idler puller, or maybe the alternator. Anyway I did 2 pulleys and the tensioner plus alternator this weekend. The noise is gone. Sometimes the cheapest explanation is the best.
Sometimes.
Now that the deafening noise is gone, I can hear all kinds of other horrible noises that were less apparent. Woohoo!

 

Turn up the radio.

 

Use the Force Luke

 

Don't forget to check the ace pump. Mine quiet down quite a bit after I changed its oil.