"Melodies of Life" is the theme song of Final Fantasy IX, and consists primarily of two themes that were frequently used in the game itself, the Overworld theme (Crossing Those Hills), and a lullaby that is sung by Dagger.
In some games, especially those that have a "level select" style of overworld (e.g. a lot of old-school 2D platform games), portions of the overworld become available for play as certain tasks are completed (e.g. beating a particular level or discovering a secret hidden within a level).
Written by Albert Hammond and Mike Hazlewood, "Gimme Dat Ding" was one track from their musical sequence "Oliver in the Overworld" which formed part of the British children's show Little Big Time hosted by Freddie and the Dreamers; this narrated a surreal story of a little boy seeking the parts to mend his Grandfather Clock.
The Super Mario Bros. theme can be heard in the Special Zone if the player leaves the overworld screen open for a few minutes.