Near-Victory Fanfare

If you're close to victory in a fight or otherwise have an advantage, sometimes you'll get a theme playing to tell you. Can happen in all games. Especially likely in boss battles.

This serves two main purposes. First, it tells the player that he is close to victory, something that may not be immediately clear from the data on the screen, particularly with Marathon Bosses. Secondly, a good dramatic near-victory theme can get a player's blood going and make the game more exciting. This potentially makes use of a Variable Mix.

Examples of Near-Victory Fanfare include:

Action Adventure

Compare Blizzeta 2 to Blizzeta 3, during the Blizzeta boss fight in Twilight Princess.
- For TP in general, whenever Link starts whailing at a boss' weak point, the musical score briefly becomes extremely triumphant.
Shadow of the Colossus tends to play "The Opened Way" when you've managed to climb up onto a Colossus and can start to kill it.
Played with in NieR, where as final battle with the Shadowlord draws to a close, the Shadowlord's dramatic theme grows quieter until a music box version of his theme plays instead, signifying his utter despair and complete loss of hope.

Action Game

For every world boss and Crush Bomber battle in Bomberman Generation, once the boss' life is down to around a heart and a half the boss theme is replaced with the more upbeat battle mode theme.
In the Captain America and The Avengers arcade game, when you get a boss down to one third health, a voice shouts "Avengers Go!" and the main theme starts up.
Happens in Warriors Orochi when you eliminate most to all of the officers in a level except the last one, or a good number of the enemy mooks.
In Bayonetta, the bosses each has their own Ominous Latin Chanting theme, but except for one, once you beat them enough, that boss theme will be replaced with a short piano piece, which is later replaced by yet another theme when you use your Finishing Move.

Adventure Game

Ace Attorney has its multiple "Investigation" themes, which intensify based on how close you are to causing the witness to spill their proverbial beans.
In the fistfighting sequences in Indiana Jones and the Fate of Atlantis, the fight music changes to a more epic, upbeat theme when either Indy or his opponent's health meter reaches yellow.

Dating Sim

Tokimeki Memorial 2 has a variation of this. When trying to win the heart of Ensemble Darkhorse Broken Bird Kaori Yae, if you manage to get her to Tokimeki State and see her mandatory Event where she confesses to the male hero her painful past, allowing her to heal her heart and turn back to the Genki Girl she was, her somber, quiet Leitmotif tune will change to a more peppy, cheerful version, meaning you're on really good tracks towards getting her Happy Ending.

First Person Shooter

During the finale of each Left 4 Dead campaign, the "Skin on our Teeth" theme will play when the rescue vehicle arrives, and the Survivors are only a short sprint from completing the campaign. (Left 4 Dead 1 version, Left 4 Dead 2 version)
In Battlefield 3, when your team has whittled the opponent down to the last 10 tickets, you will hear this in the background.

Platform Game

Once you get Dracula below half his health in Super Castlevania IV, Simon Belmont's theme replaces Dracula's on the soundtrack.
During the second halves of the final bosses in Sonic Unleashed and Sonic Colors, an awesome orchestral remix of the games' main themes starts to play. Also counts as Dark Reprise or Triumphant Reprise.
Kind of happens in Eversion: On the final stage, you have to work your way back to World 1 in order to finish the game, and the music gets brighter and more cheery as a result.
In the fights against Bowser in Super Mario Galaxy, the already-kickass battle theme gains an extra layer of Ominous Latin Chanting whenever you successfully counter his attack and are set up to deal damage.

Puzzle Game

Tetris DS has its Push Mode based on Donkey Kong. As you come closer to victory, the 25m music gains an upbeat drum beat, adds a melody and then becomes the hammer theme from the same game.
The music in Dr. Robotnik's Mean Bean Machine (and probably Puyo Puyo as well) gradually changes depending on whether you're winning or your opponent is.
The Taisen Puzzle Dama series also use this, as well as an "about-to-lose" tune, depending on whether you're winning or losing. The tunes are different depending on the version of the game.

Real Time Strategy

Some games play this trope straight whenever a large battle happens, i.e. in Dawn of War and Age of Empires III. Of course, it's not necessarily your victory.
Command & Conquer: Red Alert 3 does it with Rock Music.

Role Playing Game

Reversal! and Turn the Tide in The Last Remnant, which play when your team have the advantage of high morale. Reversal! also plays when you're on the brink of defeating the final boss.
The first three Boktai games all have the Pile Driver music, which gets steadily more epic as you get closer to purifying the boss.
Ultima Underworld II has three battle themes: one when you're close to victory, the standard one, and one when you're close to defeat.
Nearly all of the Fire Emblem games have a tune that plays when you've cleared out most of the enemies (in the GBA/DS games, its when there's only one enemy left on the map - and its often the Boss, but not always), which can get annoying if you grind for Supports.
- Fire Emblem Thracia 776 also has a near losing tune for when your units are getting killed off or when you are caught in a very bad situation in the chapter.
Pokémon Black and White plays a remix of the Pokemon theme when a Gym Leader is down to his/her last Pokemon. Also a Theme Music Power-Up.
Skies of Arcadia has this for the boss battles. The one for the final boss battle is particularly epic.
Played with in Ar tonelico II: Melody of Metafalica during the last part of Final Battle versus (the spirit of) Infel and Nenesha. The music is all glorious in contrast to the previous two parts that are full of hatred and rage... but it's only because they are about to execute the last part of SUBLIMATION.
Similarly in Parasite Eve, the Final Battle versus Ultimate Being. The music change to upbeat as he(?) evolves to adult form.
"The Genesis" in Persona 4 is an oppressive, somber True Final Boss theme with bombastic brass and ominous drums. As the battle rages, however, a heroic reprise of "I'll Face Myself"'s main melody breaks in; eventually, the music becomes an all-out, triumphant version of "Reach Out To The Truth."
About half the final fight of Mass Effect 3 will be without music, with the screams and sounds of battle being the only things you'll hear. But then, when things get the most hairier this theme will start playing. It could be considered a Near-Victory Fanfare for each side, since both armies could win at any moment (especially the enemy), and the one who wins the fight will accomplish their objectives.