Fun story: in childhood I played with father's vinyl and reel-to-reel magnet tapes. They had different recording speeds and typically I could easily guess which

Fun story: in childhood I played with father's vinyl and reel-to-reel magnet tapes. They had different recording speeds and typically I could easily guess which is correct by funny singer voice. Until I discovered Jean-Michel Jarre -- I had listened for hours, but haven't been able to figure out which speed was the correct one.