stpastor wrote:It's from The Legend of Zelda: Ocarina of Time. The musical instrument is an ocarina and it allowed Link to travel to the past and back to the present.
Alright, not to nitpick too much, but while it is indeed the Ocarina of Time and is present in Legend of Zelda: Ocarina of Time, the ocarina had no time-travel capabilities in that game (aside from accelerating to the next day/night from the Sun Song, but that could be done with the regular ocarina as well). It opened the door inside the Temple of Time to the Master Sword (legendary blade), and when kid Link attempts to draw the sword, he gets sealed away for 7 years (because he was not of age to become the Hero of Time). Upon returning the sword, it undoes the 7-year seal and sends him back to the time when he was a child. So really, in LoZ:OoT, it's actually the act of drawing and returning the Master Sword inside the Temple of Time that causes time travel.
Verily, the shirt is referring to the sequel game, Legend of Zelda: Majora's Mask, where playing the Song of Time on the Ocarina of Time would send Link back to a fixed point in time. It is in this regard that the ocarina is a time traveling device. (Though to get even more geeky about it, Majora's Mask takes place in a parallel universe, which is why the Ocarina of Time possesses this ability in the latter game but not the former.)
Anyway, I would have been overjoyed to see a cell phone referencing Steins;Gate in this list.