Harp of Ages
The Harp of Ages is a mythical instrument (from the game Oracle of Ages) that was in possession of Nayru, the Oracle of Ages. However, after an unfortunate series of events, Nayru passes it on to Link to aid him in his quest to save Labrynna.
The Harp of Ages allows its player to control the currents of time and warp between the past and present ages of Labrynna by playing certain tunes on it. The three tunes Link learns to play on the Harp are the Tune of Echoes, the Tune of Currents, and the Tune of Ages.