In a shocking upset, jazz artist Esperanza Spalding won best new artist at the Grammy Awards on Sunday night (Feb. 13), beating out widely agreed-upon favorites Justin Bieber and Drake as well as Mumford & Sons and Florence & the Machine.

Feature: Esperanza Upclose

"I take this honor to heart so sincerely, and I will do my damndest to make a whole lot of great music for all of you," said Spalding while accepting her trophy, as a visibly surprised Bieber looked on.

Video: Billboard's Best New Spotlight on Esperanza Spalding

Already, fellow artists has congratulated Spalding via Twitter. "Wow. Awesome upset!" tweeted the Roots drummer ?uestlove. "We are floored! couldn't happen to a nicer person."

Kanye West, meanwhile, appeared to be holding his tongue for a change, tweeting, "Damn... I can't find the words to explain how I feel about the best new artist award...Don't wanna say the wrong thing."

Despite his expression of disappointment on camera, Bieber seemed prepared for any outcome at the Grammys earlier today, writing on Twitter, "Regardless of what happens today is a GREAT DAY...so blessed and grateful. This is just the beginning."

Spalding's Grammy nominations came on the heels of her most recent album, "Chamber Music Society," which reached No. 1 on Billboard's Heatseekers Albums Chart and No. 3 on Top Contemporary Jazz Albums. The 26-year-old singer/bassist composer most recently appeared on the bill for Prince's upcoming "Welcome 2 America" tour.

What do you think of the Grammys pick for best new artist? Were you surprised? Share you thoughts in the comments.