From Glitch City Laboratories
A trade via the mobile adaptor which was only released in Japanese versions of Pokémon Crystal, when you first connect the mobile adaptor it will play music never heard in the English versions of the game.
|This article is a summary page for variations of certain glitches or phenomena such as Pokémon Cloning, glitch myths, beta elements, or a collective term for variations of glitch Pokémon which share similar names, sprites or other information.
Most soundtracks present within the Pokémon games have been applied to at least one map, or other in-game interfaces such as the title and the battling system. However, various songs and sound effects exist in the Pokémon games which are never actually used without an external device.
Several of these tracks have, arguably, been composed to account for music from older games. For example, a remixed version of the title screen music from Pokémon Ruby and Sapphire exists in Pokémon Diamond and Pearl; however, it is never used in normal gameplay. Other tracks serve a completely unknown purpose, such as an unused theme from Pokémon Battle Revolution. It is also notable that an off-key version of the original music from routes 206, 207, 208, and 211 accounts for several hundred inaccessible areas entitled Mystery Zone in Pokémon Diamond and Pearl.
Unused soundtracks in Generation I
In Pokémon Yellow:
Only one unused track is currently known to exist within Pokémon Yellow.
- An unknown, unused track exists within the coding of Pokémon Yellow. Interestingly, it does not exist within Pokémon Red and Blue, which may suggest itself as part of an additional planned feature. This hypothetical feature however, does not exist within the final game, unlike the Pikachu surfing minigame for example. It has also been suggested that this track may be part of the unused "Hurry, get away!" battle system, but this is unconfirmed. 
Earlier song versions
In Pokémon Red and Green:
- Lavender Town - In Version 1.0. of Pokémon Red and Green; the first version to be sold to the public, a slightly different version of the Lavender Town track exists within the game. This version of the track however, was later changed in later editions of the games. Compared to the later versions, this version of the track uses some notes which tend to be only heard by younger players, as they are of a high frequency and consequently of a higher pitch. For this reason, the track may have been removed to prevent players from the rare occurence of any mild side-effects associated with the notes, such as headaches and nausea. 
Unused soundtracks in Generation II
In Pokémon Crystal: Three unused tracks exist in non-Japanese versions of Pokémon Crystal, but only one unused track remains in the game when considering all languages.
- A completely unused track exists in Crystal for unknown reasons occupying slot 91 (5B); it is similar to the music played in the Battle Tower or that of a town. 
In Pokémon Stadium II:
- A remixed track of the same unused song mentioned above exists in the English version of Pokémon Stadium II, it was however used in the Japanese version for battles against other players.
Japan exclusive tracks (Generation II)
As a method to obtain the GS ball to capture Celebi in Pokémon Gold, Silver and Crystal, the Poké-Communications Centre (PCC) was built into the final release of the Japanese versions of the games. A mobile-adapter was sold separately which allowed the player to initialize the event by downloading it on their mobile and transferring it to their Pokémon game. However, since these features were never included in other versions of Pokémon Gold, Silver and Crystal, two extra unused tracks exist in non-Japanese games.
- The music which plays when the player connects the mobile adapter. 
- The music played in the Poké-Communications Centre. 
Unused soundtracks in Generation III
Several unused tracks exist in Generation III which seem to be remixes of old songs from Generation II, such as Team Rocket's Theme. However, other tracks such as an unused track similar to Littleroot Town may have been used as test music. In Pokémon Mystery Dungeon: Red and Blue Rescue Team, two unique, unused tracks also exist within the game.
In Pokémon Ruby/Sapphire:
The following unused tracks exist in Pokémon Ruby and Sapphire.
- An unused track which is a slightly different arrangement of Littleroot Town's theme exists in the game. 
- A remade version of the music played in the Poké-Communications Centre exists in the game but is never used. 
- A remade version of Team Rocket's Theme is another example of a track which exists in the game but is never used. 
- A remade version of the theme played when encountering Raikou, Entei or Suicune on Pokémon Crystal exists within the game, but is never used because Nintendo decided not to include the legendary dogs in Pokemon Ruby, Sapphire, and Emerald. However, Pokémon Colosseum and later Pokémon Firered/Leafgreen decided to use the normal Cipher Admin music and the normal wild Pokémon music for the legendary dogs, respectively. 
- A remade version of the music from routes 38 and 39 exists within the game, but is never used. 
- A remade version of Pokémon Gold/Silver's original Pewter City/Saffron City remix exists within the game, but is also never used. 
An unused set of sound effects also exist within Pokémon Ruby/Sapphire, portraying a robotic feminine voice. These sounds may have been used to test the byte to play audio independently from the actual music itself. Additionally, perhaps Nintendo also intended to create a female character similar to The Bard in Pokémon Emerald, who would also 'sing' a song to the player, based on the words he or she inputs. 
In Pokémon Mystery Dungeon: Red and Blue Rescue Team:
Two unused tracks have been found within the coding of the original Pokémon Mystery Dungeon games.
-  - A cheerful tune, which exists for unknown reasons.
-  - Another cheerful tune, possibly orginally intended for the Pokémon Plaza.
Unused soundtracks in Generation IV
In Pokémon Diamond/Pearl:
- A remix of the title screen music from Pokémon Ruby, Sapphire and Emerald exists in the game entitled "SEQ_TEST_TITLE". As its name suggests it is most likely a placeholder to test that music on the title screen will play correctly before the actual title screen music was composed. 
- A slightly off-key version of routes 206, 207, 208 and 221 is played in most of the several placeholder areas entitled Mystery Zone within the game which exist in between real locations. It is named "SEQ_DUMMY", which suggests that it is to compensate for music in these locations which would otherwise be undefined. 
- Exclusive music for a battle against the Tower Tycoon in the Battle Tower exists within the game, but is never used for unknown reasons. Nintendo decided to use the Champion Battle Theme instead. This music is a slightly different version of both the music played against a Gym Leader and a member of the Elite Four. 
- An alternative arrangement for the music in Jubilife City exists and can sometimes replace the music of areas named "Jubilife City" while in the tweaking void.
In Pokémon Mystery Dungeon: Explorers of Time and Darkness:
-  - A remixed version of the Makuhita Dungeon from Pokémon Mystery Dungeon: Red and Blue Rescue Team exists within Pokémon Mystery Dungeon: Explorers of Time and Explorers of Darkness but remains unused, likely because of the fact that the Makuhita Dungeon was not included in these games. This may imply that a similar dungeon was originally intended, or that the sequels were based off of the original games.
In Pokémon Battle Revolution:
- Unused music exists for possibly an extra colosseum or waiting screen. It is a rather smooth and steady theme which could have once been planned for Neon Colosseum 
- Many files denoting the narrator's speeches in Pokémon Battle Revolution exist but are completely blank and are never used in the final game, which may suggest that these are deleted versions of speeches from an earlier version of the game.
- A file denoting one of the narrator's speeches exists as "ba120_0". In this speech, the narrator says "Lagoon Colosseum, Tournament Battle, first match." This may suggest that at least at one point in the game's development Lagoon Colosseum was intended to be featured in one of the main Tournament challenges. This track is never used in the final game because Lagoon Colosseum is only accessible via a Random Wi-Fi Match, a Friend Battle or the DS Multiplayer Mode. 
- In the file "la030_0", the narrator speaks the words "Surrounded by cascading water, the battle is about to begin." This file is never used in the final game and may have once been associated with Lagoon Colosseum as backed up by the narrator's description of the area and the final name "la030_0" where "la" may be an abbreviation of Lagoon.