Google or iPhone or God/Bill Gates should really come up with an application to which you can hum those 5 notes to a song that you cannot place but has been in your head all afternoon since that dude walked down the hall whistling it and you would give anything to know who that was just so you can hunt him down and ask, "FOR THE LOVE OF GOD, WHAT SONG?!?!", stranger or no, so then you would Know! The! Song! and thus purge it from your brain.