I was going to say that Oingo Boingo was originally called The Mystic Knights of the Oingo Boingo, but apparently the latter was actually a street theater troupe that kind of evolved into the band.
And, they appeared on The Gong Show!
Seriously, you could never keep it a secret now. I believe these Bingo Hand Job concerts were at a tiny venue in London called “The Borderline.” They also featured guest appearances by Billy Bragg and Natalie Merchant, according to my tapes, anyway 
I think the band members stressed that, despite the name change, the heavy metal umlauts meant that the new name was still pronounced like “Green Jello.”
Simon & Garfunkel were originally Tom and Jerry, which was just. . .wrong.
Hotlegs had a hit in “Neaderthal Man” and put out two albums in the UK, but once sales dried up, the musicians rebranded themselves at 10cc and became a massive success with several hit albums and singles, notably, “I’m Not in Love.”
And also spurring an oft-repeated story (denied by the band’s members during their heyday) about the origin of the name: that 10 cubic centimeters was the average volume of a male human’s ejaculate.
Just the amount to make a spoonful, after which the Lovin’ Spoonful were named (to be precise, after the Mississippi John Hurt song of the same name).
There was a Southeastern regional band ca. 2000 (+/- 10 years or so) that had a bassist named Mike Mills. Their gig flyers would say “Featuring bassist Mike Mills” and their shows would sell out.
And Mr. Mills WOULD walk out on stage, just not THAT one.
Maybe they could toss him in the same prison as Lostprophets’ singer Ian Watkins. You REALLY don’t want to know what Watkins did.
My brother was a college DJ when the Reverb Motherfuckers put out an album. They only played it between midnight and 6am, when the FCC rules about profanity, etc. didn’t apply.
Speaking of Mickey, should he decide to tour again he’d be The Monkee.
The late 1980s band the Cult started out as a punk band called Southern Death Cult, complete with mohawks.
TW4 used to play at my high school dances fairly frequently, although I never saw them there. It was many years later, after I had been listening to Styx for years, that I learned that Styx and TW4 were the same group.
Though retroactively oddly appropriate to decades of on-again off-again animosity.
If not for Robert Heinlein, they would have been the Planet Earth Rock and Roll Orchestra.
That’s Blows Against the Empire, a concept album about hippies hijacking a starship. “Hijack” is the centerpiece song, and the concluding track is “Starship,”
which relates a mutiny fought for control of the ship, to determine whether to surrender and return, or to continue. Eventually the idealists win control and the ship is flung by gravity slingshot around the Sun and out of the Solar System.
By Kantner’s admission, the underlying premise of the narrative was derived in part from the works of science fiction author Robert A. Heinlein. In Heinlein’s novel Methuselah’s Children, a group of people hijack a starship. In the song “Mau Mau (Amerikon)” Kantner quotes a line from the novel where the hijackers turn on the ship’s drive. At this point the main character of the novel, Lazarus Long, says “Push the button, pull the switch, cut the beam, make it march.”
Kantner went so far as to write to Heinlein to obtain permission to use his ideas. Heinlein wrote back that over the years many people had used his ideas, but Paul was the first one to ask for permission, which he granted. In 1971, Blows was the first rock album ever nominated for a Hugo Award in the category of Best Dramatic Presentation.
Kantner’s ad hoc supergroup of Airplane, CSN, and Grateful Dead members were called “Jefferson Starship” in the album credits, but it’s obviously not the same band as the “Ride the Tiger” Jefferson Starship. Before they took that name, they were the Planet Earth Rock and Roll Orchestra.
Maybe it would have been a good idea to change: Ian Anderson. He does use his middle initial (Ian A. Anderson), but it doesn’t prevent confusion.
His website says “Oh, and I have two legs and don’t play the flute. That’s a different Ian Anderson.”
David Bowie’s first few singles were issued under the name Davie Jones.
Three guesses why he changed it!
Johnny Blue Skies originally went by the name of Sturgill Simpson.
Glad Johnny decided to go with his real name rather than that ridiculous nom de plume.
Great decision by the brothers.
Little pig, little pig, let me in! I grew up when that video was on MTV every freaking hour it seemed.
There’s an old video clip out there of a visit to England by an American musician (can’t recall who). He’s greeted by a fan club, the president of which is a very young David Bowie.