This is an experiment that I did with feedback around 2006 with a PZM mic. The tweeter of the powered speaker I used had a built in limiter but I used additional compression in the signal chain to protect the wolfer from being damaged by volume spikes. I rhythmically lifted and lowered the levers of various frequencies on a graphic equalizer to excite and retard the feedback of certain frequencies. The process was a bit haphazzrd because there are so many variables that can influence the way the feedback behaves and so it would be difficult to recreate the exact conditions. And it still seemed like it was a bit hard on the speakers even with all the limiting and compression for protection. However I did manage to create a few nice melodies.