Feb. 15, 2011 -- Jazz artist Esperanza Spalding's surprise win over teen pop music singer Justin Bieber at Sunday night's Grammy Awards prompted some upset Bieber fans to unleash their anger online.
It left pop fans scratching their heads and jazz fans wondering how an artist who's been around since 2006 was new.
Even Spalding was surprised by the honor.
"I really wasn't expecting that at all. So I was surprised. I looked at my brother and said, like, really, and he said, 'yes, go!'" Spalding said backstage at the show.
A former child prodigy who taught herself to play violin at age four, Spalding has performed at the White House more than once -- including during President Obama's Nobel Peace Prize acceptance speech.
A 26-year-old jazz singer and bassist from Portland, Ore., Spalding has performed with Prince and served as the youngest faculty member ever at the Berklee College of Music.
Her 2008 album stayed more than 70 weeks on the Billboard Contemporary Jazz Chart.
Despite her many musical credentials, some Bieber fans let out their frustration and anger over their favorite singer's loss online.
On Wikipedia, Bieber fans apparently vandalized Spalding's page noting she won the Grammy "by stealing it from Justin Bieber."
Another revised entry read in all caps: "GO DIE IN A HOLE…WHO THE HECK ARE YOU ANYWAY?"
On Twitter, fans questioned the prize bestowed to Spalding.
"Congrats... on your 5069 followers," one Bieber fan tweeted bitterly.
"Were any of YOUR albums on top of the Billboard 200?" demanded another.
This isn't the first time fans of the 16-year-old Canadian have reacted so strongly over the teen sensation's personal life.
As late night host Jimmy Kimmel recently noted on his show Friday, Bieber's fans can be vicious.
"Every time you seem to be interested in a girl or a girl seems to be interested in you, there are death threats," Kimmel told Bieber, who was a guest on his show.
Earlier this month, when Kim Kardashian and Bieber exchanged complimentary Twitter messages and the pictures of them together, Kardashian received death threats from Bieber fans.
"It was all in fun, literally I could be his mother," she said on Kimmel's show. "And like it's so weird that people would ever think we were dating."
Last year, angry fans turned to Twitter after Bieber was seen with teen pop star Selena Gomez.
Gomez was bombarded with death threats.
But Bieber handled the loss with charm. Backstage at the Grammys, Bieber congratulated his rival.
"I'm happy for you," Bieber told Spalding.
It turns out Bieber is in good company.
"Every major top tier artist in the last 50 years, only one, the Beatles, has won a big Grammy. Only one," said Bill Wyman, a rock critic for Slate.com
Even Spalding said backstage at Sunday's show, that Bieber has a full career ahead of him.
"He's going to have many more years and many more nominations so I think he'll be great," she said.
ABC News' Sheila Marikar contributed to this story.