Having Bob Dylan in the studio is torture enough, but that wasn't all that happened. On top of that, we had flubbed lines, technical difficulties, and a few other celebrity guests when my voice slipped from one impression to another.
Writing and recording parodies is hard work (especially when you're pretty much on your own, sans a few special guests from time to time), but it's also a lot of fun, as you can see... Er... Hear. The trick is to have fun with your mistakes.