Soundtracks are one of the most memorable things about a work. Ofttimes, a work will have one (or many) tunes that, when you hear them, just immediately make you remember the work in question. And then there are those tracks that you associate so much with the work that the absence of it feels like Early Installment Weirdness.
This could be related to many things. For instance, a particular theme could be associated with an Iconic Sequel Character (such as the theme of Rohan from the The Lord of the Rings trilogy), it could result from a particular composer just penning something magnificent that so happened to come later in the series, or it could be because one particular track just struck a chord with audiences. Whatever the case, if you hear a song from a score and it makes you instantly think of the series as a whole, and it doesn't appear until after the first installment, you have yourself an Iconic Sequel Song.
As mentioned above, related to Iconic Sequel Character, where it's the character him/her/itself that appears late. See also Bootstrapped Theme, which is when a particular song unofficially becomes the main theme of a particular franchise, as many of those listed below are bootstrapped themes for their franchises.
Film - Live-Action
- As mentioned in the main article, the motif for Rohan and the theme of Minas Tirith did not appear until The Two Towers and The Return of the King respectively.
- The hit song "Eye of the Tiger" is most commonly associated with the Rocky franchise and is rivaled only by the original instrumental theme "Gonna Fly Now" in fame, but it didn't debut until Rocky III.
- A number of Star Wars songs did not appear until later films, but most notable is "The Imperial March," which didn't appear until The Empire Strikes Back. The Empire's theme was a sinister, brassy triad in a minor key in A New Hope.
- In A Song of Ice and Fire, many songs associated with the universe don't appear until A Storm of Swords, including "The Bear and the Maiden Fair" and "The Rains of Castamere." In the television adaptation, "The Rains of Castamere" appears a bit earlier, being introduced in the second season.
- Star Trek is often associated with the theme of the movie/Star Trek: The Next Generation despite the original theme being something else.
- The main recurring theme used throughout Crash Bandicoot 3: Warped would end up recycled in many later titles, becoming something of a Bootstrapped Theme for the series.
- Final Fantasy:
- The Chocobo theme doesn't appear until Final Fantasy II, later expanded in Final Fantasy III.
- The Moogles' theme doesn't appear until Final Fantasy V.
- Dancing Mad and One-Winged Angel don't appear until Final Fantasy VI and Final Fantasy VII respectively despite being the poster-children for final boss themes across the franchise.
- Kingdom Hearts has several well-known themes, such as "Sanctuary," "Darkness of the Unknown" or "Vector to the Heavens" that didn't appear until sequel games.
- The Legend of Zelda:
- "Zelda's Lullaby" has appeared in almost every Zelda title since Ocarina of Time. It first appeared in A Link to the Past as a tune when you're escaping with Zelda out of the dungeon at the start of the game.
- The motif for Ganon/Ganondorf isn't introduced until The Legend of Zelda: A Link to the Past, and then expanded in The Legend of Zelda: Ocarina of Time.
- The Hyrule Castle theme and the Fairy Fountain are also first heard in A Link to the Past.
- The themes for Zora's Domain, the Lost Woods/Saria's Song, the Kokiri Forest, Epona's Song, and Goron City first appeared in Ocarina of Time.
- Super Mario Bros.:
- If Mega Man had a song that would be forever considered the franchise's theme, it would likely be the title screen music... from the second game.
- In Metroid, Ridley's Theme, Kraid's Theme, Upper Brinstar, and the Lower Norfair/Magmoor Caverns theme didn't appear until Super Metroid. The former two were just standard boss music until later games brought them back to associate themselves with their namesakes.
- The song "Philistine" is one of the most iconic in the No More Heroes series, but it doesn't appear until NMH2.
- Theme of Eastern Story, a Recurring Riff in Touhou, was not introduced until the fourth game in the series.
- Nostalgia Critic's theme song didn't premiere until the post-The Review Must Go On era.