There are seven variations of this track. The Mettaton variation does not play in-game, and only two of these variations are included in the official Undertale Soundtrack: Start Menu, and Menu (Full). Menu (Full) plays at the end of a True Pacifist Route and before completing the game.
Every subsequent iteration of this track adds instrumentals directly related to how many characters the protagonist befriends.
|Default, contains only square wave melody, and a noise channel imitating a snare drum.|
|Spared Toriel, adds syncopated bassline from the source material, Once Upon a Time.|
|Befriended Papyrus, adds a piano harmonizing the melody, and doubles the bassline.|
|Befriended Undyne, adds more square waves to the harmony, and adds bongos.|
|Befriended Alphys, adds strings doubling the piano's part, and adds claves.|
|Unused, adds glockenspiel doubling the melody.|
|Saved Asriel Dreemurr. Adds sustained strings, and counter-melodies from the piano. It also quotes the C section from Once Upon a Time, from 0:21-0:32. mus_menu6 also acts as a separate track in the OST, Menu (Full).|
|Undertale Demo Soundtrack|
|1 - 10|| Once Upon a Time • Menu • Your Best Friend • Fallen Down • Ruins|
Anticipation • Unnecessary Tension • Enemy Approaching • Ghost Fight • Determination
|11 - 16||Home • Heartache • End • Nyeh Heh Heh! • Home (Music Box) • Empty House|