So, I know it's came up many, many times before about how Guitar Hero is a rip-off of this game or that game, and how said game is just a rip off of another game...
But, is it possible, I've found the grand-daddy of all music-rhythm video games?
http://www.youtube.com/watch?v=6ee1TV7wMYc&NR=1Melody Blaster - the only title released for the Music Synthesizer add-on for the Entertainment Computer System add-on for the Mattel Intellivision. Released in 1983, this game came out 16 years before Guitar Freaks, 15 years before the first Dance, Dance Revolution game, 14 years before the first Bemani game, 13 years before Parappa the Rapper 12 years before Harminox ever existed, and four years before Bandai's Dance Aerobics.
What an odd piece of history here...