Epona's Song

"Epona’s Song" is a recurring melody played by Link in the to call Link's horse, who is usually named Epona by default. It is mentioned in Ocarina of Time that "Epona's Song" was composed by Malon's mother.

Music Theory
The full version of Epona's Song is in binary form, with 16 bars in both the A section and B section for a total of 32 bars with a 4-bar intro. The entire piece consists of 4-bar phrase lengths, is played with a slight eighth-note swing, and is in 3/4 time. It should be noted that this is the only piece in the whole game the uses a swing eighth-note rhythm. Even more unusual is the fact that the vocal part does not follow the swing rhythm and instead plays it straight, a technique commonly used to create rhythmic clash and a little bit of tension.

Harmonically, the A section is based in D Major, although the tonic basis is fairly ambiguous until the 8th bar which gives a V7 chord (A7) going into I (D). The B section is based in F Major with great harmonic variety, ultimately ending in another A7 which provides a smooth turnaround into the A section again.

Ocarina of Time
In Ocarina of Time, "Epona’s Song" can be learned from Malon, Epona's owner, in Lon Lon Ranch when Link is a child. Initially, Link can play this on his Ocarina to tame Epona and beck her to come. After the horse is won from Ingo at Lon Lon Ranch, playing the song as an adult allows Link to call Epona and ride her. Whenever this song is played, Epona travels to wherever Link is in Hyrule Field, Lake Hylia, Gerudo Fortress, and some other outdoor areas.

If Link has an empty bottle, “Epona’s Song” can also be played around cows to earn milk.

Malon can be heard singing this song in Hyrule Castle as a child or at night at Lon Lon Ranch as an adult, depending on how much the game has progressed.

Majora's Mask
"Epona's Song" can also be played on Link's ocarina to call Epona in Majora's Mask, but only after Link first finds her in a stall at Romani's Ranch. Once again, it is only effective in areas Epona can reach, such as Termina Field or certain portions of Great Bay Coast. "Epona's Song" is taught by Romani after Link agrees to help her save the ranch from the Ghosts.

The Minish Cap
"Epona's Song" makes a cameo appearance in The Minish Cap. Every time Link speaks with Malon, this melody will play.

Twilight Princess
Although "Epona's Song" appears again in Twilight Princess, it may not be as one would expect. Despite that it still calls Link's horse, rather than playing a musical instrument, Link must blow into a piece of Horseshoe Grass to perform the song initially. Later on, the portable Horse Call allows this song to be played anywhere, instead of just where certain patches of grass can be found.

While in Wolf Form, Link can howl the song to summon Epona whenever he's near a patch of Horseshoe Grass. However, he can only ride Epona while in human form.

Ilia's theme is also a rearranged "Epona's Song."

Super Smash Bros. Brawl
In Super Smash Bros. Brawl, "Epona's Song" is part of the "Ocarina of Time" medley, and it appears alongside other familiar melodies such as the "Song of Storms", "Zelda's Lullaby", "Saria's Song", and the "Song of Time."

Trivia

 * Wind's Requiem from The Wind Waker uses the same arrow directions to play the song as Epona's Song does.
 * A vocal version of this is sung by Emiko Shiratori, and available in the Ocarina of Time Re-Arranged Album. The vocal version of the song was also sung in the Mario and Zelda Big Band Live Show, which was also released on soundtrack.
 * In Twilight Princess, a remixed version of the song can be heard while calming Epona down in Kakariko Village.