Wind's Requiem

The "Wind's Requiem" is the first song Link learns in The Wind Waker. It is learned upon reading a monument behind Dragon Roost Island with the notes inscribed on it. This melody allows Link to control the direction of the wind, but it only works outside.

The "Wind's Requiem" plays a major role in The Wind Waker, for it is necessary to constantly change the direction of the wind in order to navigate the many islands of the Great Sea. In later parts of the game, playing this melody on certain tiles will make a treasure chest appear, usually containing a Triforce Chart in the Great Sea or a Treasure Chart in some dungeons.

Trivia

 * Interestingly enough, the "Wind's Requiem" can be used to change the direction of the wind during the final boss battle against Ganondorf on top of his tower, although doing so does not change anything with the outcome of the battle.
 * "Epona's Song" has the same directional notes as the "Wind's Requiem".
 * The Winds Requiem sound very similar to and may be based off of the Song of Time.
 * Similarly to Zelda's Lullaby, the Wind's Requiem is another alleged reference to the Triforce, with one directional note for each crest of the Triforce.