I'm not sure if this was already mentioned here, but there's a free little app that you can use to figure out the tuning frequency (438, 440, 442...whatever) of a song.   Technically it's a demo of the tONaRT library, which the company is licensing to pro audio software manufacturers, but it serves our purposes just fine.   You can download it here: http://www.zplane.de/index.php?page=description-tonart ("download demo" button in the top right corner).   The song you wish to analyze has to be in