Famous musicians who had hits before they were 18.

#1 country album and #6 country single when she was 17, so I agree that she qualifies.

The amazing 17 year old Lesley Gore.

Wynnona Judd was the youngest person to be signed to her record label since Elvis.

Björk recorded her first album when she was ten. (She turned eleven just before its release.)

She sounded exactly the same, it’s pretty amazing.

Are you serious? That’s a ridiculous comparison, as when Shirley Temple was a child, sheet music sales were a big deal and since then recorded music sales (wax cylinders, 45s, LPs, CDs, digital downloads, etc.) are the vast majority of music sales.

And the only person below the age of majority to be inducted into the Rock and Rock Hall of Fame.

Brenda Lee

I… I think that was a joke.

At 13, Frankie Lymon sang lead on the aptly named Teenagers’ #6 hit “Why Do Fools Fall in Love,” had a handful of other hits, and was dead by 25 of a heroin overdose. And he was damn good.

ETA: Oh, crap, that was in the OP! Oh well. I’ll take any chance to give him props. I love Frankie.

I thought for sure Wayne Newton would qualify with Danke Shoen but, born in '42, that became a hit in '63. He sure sounded and looked a fair bit younger.

OK, that makes sense. As to the OP, how about Charlotte Church?

In addition to those already mentioned:

Kris Kross hit with “Jump” in 1992 when both members were 12
Little Peggy March hit with “I Will Follow Him” in 1963 when she was 15
Janis Ian hit with “Society’s Child” in 1967 at age 15
Little Eva hit with “The Loco-Motion” in 1962 when she was 16
Fabian hit with “I’m A Man” in 1959 when he was 16
Ricky Nelson hit with “A Teenager’s Romance”/“I’m Walkin’” in 1957 at age 17
Charlie Sexton hit with “Beat’s So Lonely” in 1986 when he was 17

In the classical field, ‘hit’ is a little more difficult to nail down. There are composers like Mozart, Bizet, Mendelssohn who were composing at a very young age. Hit, though? Hmm. In all three of their cases, they are remembered much more for works they wrote in their maturity. Their early works are remarkable for the age at which they were written, but they aren’t generally held up as great compositions in their own right.

What about classical performers who made their debuts at young ages? Granted, they may not be performing their own compositions, and a lot of their success is based on how well they did throughout their careers. It’s hard to ignore, however, that Yo-Yo Ma performed for JFK at the age of 7, or that Akim Kamera performed with Andre Rieu at Radio City Music Hall at the age of 5.

Wiki has a list of musical prodigies of many different genres that is quite interesting to wade your way through.

Rebecca Black

Erich Brann (sp?), Iron Butterfly guitarist, 17 years old when In A Gadda Da Vida hit the charts.
And I am mildy irritated that it took all of four posts for someone to beat me to Mozart. I thought I was going to be so clever.

Not exactly a “hit”, but Shuggie Otis was all of 16 when he played bass on “Peaches En Regalia” (Frank Zappa’s Hot Rats album).

Moon Zappa, “Valley Girl”, age 14.

Britney Spears and Christina Aguilera both had their first hits at age 17.

Without consulting the lst I nominate Camille Saint Saens, who reportedly was an astonishing prodigy at the piano. Capable of playing all of the Beethoven Piano Sonatas, from memory, at age ten. (If my memory is correct.)

And now I’ll enjoy that list you linked.

Jordy.

“Dur dur être bebe.”

…what do I win?