BABS Reverb

The British Association of Barbershop Singers publishes all of the annual competition videos on Youtube. However - these videos are presented with a distinct absence of natural reverb.  Apparently this is because the judges use these videos to practice their judging, so they want them to be as controlled, and scrutable as possible...

...but we are not all judges in this life - some of us are just humble denizens of the web who want to listen to glorious 4 part harmony with ridiculous artificial 8-second Notre Dame impulse response harmonies.

This extension serves to fix the problem, by adding controllable reverb to BABS videos.