Serenade of Water

The "Serenade of Water" is a recurring song in the, first appearing as a playable melody in Ocarina of Time.

Ocarina of Time
In Ocarina of Time, the "Serenade of Water" is one of the warping songs Link learns as an adult. It is taught to him by Sheik after obtaining the Iron Boots in the Ice Cavern, and enables him to easily warp to Lake Hylia where the Water Temple is located. Interestingly, when it comes to its playable notes, it's the shortest melody in the game, and it's also shorter than any song from Majora's Mask.

Twilight Princess
In Twilight Princess, the serenade can be heard as the background music for the two instances when Link encounters the ghost of the deceased Zora Queen, Rutela. The aforementioned two moments are when the throne of Zora's Domain is found totally frozen, and after escorting Prince Ralis from Hyrule Castle Town to Kakariko Village.

Super Smash Bros. Brawl
In Super Smash Bros. Brawl, the "Serenade of Water" is heard at the end of the "Song of Storms" track alongside with Ganondorf's theme.

Etymology
A serenade, or "serenata" is a musical composition or performance in someone's honor. Serenades are typically calm, light music. In fact, the word Serenade is derived from the word sereno, which means calm, making it fitting to the smooth and relaxing tempo of the "Serenade of Water."