Theme song
Whenever Transformers has a show, it has a theme song.
Generation 1
The original, classic Generation 1 theme tune by Anne Bryant and Ford Kinder, with its simple, iconic repetition of the brand's rhyming slogans, "More than meets the eye," and "robots in disguise," has formed the basis of most Western Transformers theme tunes. Used as both the opening theme of the animated series and in the multitude of toy commercials over the years, it's pretty much burned into the mind of every twenty-something on the planet, and maybe their parents as well. You say to someone, "Transformers?" and it's not unlikely that you'll have them jingle back "Ro-bots in dis-guise!"
Seasons 1, 2 and 3 of the series feature their own distinct renditions of the theme tune, with season 3's version being especially distinguished by the unusual "Ah-aah!" chant that runs throughout it. For The Transformers: The Movie, composer Vince DiCola created several new versions of the tune (featuring instrumental pieces included in other parts of the movie's score), sung by Ed Fruge and Gary Falcone, although ultimately, the finished movie used a power metal arrangment by Lion with additional verses in between the familiar chorus.
Beast Era
As the first new Transformers cartoons since Generation 1, Beast Wars and Beast Machines featured new theme tunes that owed nothing to original; in years to come, this would make them the distinct exceptions amongst their animated brethren. Beast Wars features an instrumental theme tune with occasional roaring shouts of "Beast Wars!" (unless you live in Canada, in which case they were shouting "Beasties!"), while Beast Machines stands out even further, having licensed the pre-existing song, Leftfield's "Phat Planet," to serve as its theme.
21st century
The fandom just about wet itself when Robots in Disguise became the first cartoon since Generation 1 to employ a variation of the classic theme tune, although there were a few surprises along the way. First, an MP3 of what appeared to be the new theme tune was released online, but when the series actually debuted, everyone was a bit surprised to discover that its theme was an entirely different variation of the G1 theme, most notable for adding the new line, "Change before your eyes," in place of "more than meets the eye." The mp3 turned out to be the new commercial jingle, which featured in commercials for all subsequent lines.
Armada featured an instrumental version of the classic theme (with a narrator lecturing the audience on the premise of the show in place of lyrics), with Energon restoring the familar "Robots in disguise" and "more than meets the eye" lines. Cybertron offered a unique version of the traditional tune by Paul Oakenfold, with energetic shouts of the brand and faction names. Perhaps most significantly, it featured the return of the long-lost line, "Autobots wage their battle to destroy the evil forces of the Decepticons" - albeit simply spoken by Okenfold during the middle-eight, rather than sung.
As part of the viral marketing for the live-action movie, an mp3 of Linkin Park soundalikes "DECEPTIBOT" performing a song that included the classic theme as a chorus was released online. This song didn't feature in the movie or on the soundtrack, though - instead, Mutemath performed a whiny, emo version of the tune for the soundtrack, although it didn't appear in the film itself.
Animated stands poised to continue this tradition, with yet another new variation of the theme, including an entirely new rhyming couplet, "More than they appear/not just bolts and gears!"
