As a kid I modded my little plastic turntable after hearing about backwards messages in songs and the like. One thing lead to another and I discovered that Chipmunks album sounded heavier than hard rock if played forwards at very low speed. Fast forward to a decade or so ago and someone released it as a sludge rock album. It really is something, sounds incredibly brutal and nothing like the original with those unnaturally high voices. My Mother's snap reaction to the first few seconds of it playing will never leave me.