I'm getting a loud squealing from one of the pulleys only when I accelerate

What is your question?

The squealing is much louder and distinctly different than the common belt chirp. It's difficult to narrow down to the specific pulley just by listening to the squealing. Based on research, I'm guessing it's the idler pulley, but just wanted to educated opinions in order to avoid unnecessary time and money being used for things that aren't in need of repair.