1995 Mazda 626 Unnerving metallic sound from motor

This evening when my wife fired up the car to leave my parents house, after being there for approximately 7 hours, the car made a terrible sound. It had driven just fine, with no stuttering, stalling or other problems during the afternoon. I know there is a belt squealing, which is to be remedied quite soon. However, on top of the belts, there was a horrible metallic screeching, but not a constant note. Sounds like someone has dumped a bucket of bolts into the crank case.

To me, it sounds like its coming from the top end. Obviously, with such a bad sound, we didn't run the motor long enough to really pin point where the sound is coming from. When facing the motor, it seems to be coming from the top right side(not the side with the pulleys).

I'm curious if a mechanically failing distributor could cause this problem, as it seemed to be coming from that area. Unfortunately, I'm thinking its something deeper, as the car continued to run as if there were no issues with timing.