Got to be a bit nitpicky here, since it holds a dear place in my heart:
That honor goes at least to 1990s Loom [http://en.wikipedia.org/wiki/Loom_(video_game)], and I'd not be too surprised if even that one wasn't the first. And the mechanic was beautifully implemented in Loom.
One can (or at least could) get it for free legally at places like abandonia or the like, so give it a spin.
While OoT may be the game that brought the mechanic to a wide audience, it wasn't the one that created it by far.From the Article
Using songs played on a music instrument is still one of the most innovative game mechanics ever created.
That honor goes at least to 1990s Loom [http://en.wikipedia.org/wiki/Loom_(video_game)], and I'd not be too surprised if even that one wasn't the first. And the mechanic was beautifully implemented in Loom.
One can (or at least could) get it for free legally at places like abandonia or the like, so give it a spin.