Last night's Grammy nominations announcement had some asking "Who?" in regards to Best New Artist nominee Esperanza Spalding, but the jazz bassist/vocalist/composer has seen her share of the lime -- err, purple -- light. Besides appearing on the bill for Prince's upcoming "Welcome 2 America" tour, Spalding aced a tribute to the Purple One at the 2010 BET Awards.

Spalding arrives at the Grammy nod riding the success of her most recent album, "Chamber Music Society" (Aug. 17, Heads Up International/Concord Music Group), which reached No. 1 on Billboard's Heatseekers Albums Chart and No. 3 on Top Contemporary Jazz Albums.

"Chamber Music Society" draws from the same wellspring that inspired the Spalding's 2008 debut, "Esperanza." It's the second chapter in the evolving career of the 26-year-old touted as a breath of fresh air within the contemporary jazz establishment -- and a telling example of an artist who harbors no qualms about following wherever her muse leads.

"I might have felt pressure," Spalding says about emulating the jazz, funk and Brazilian rhythms -- accented by multilingual vocals and scatting -- that propelled her 2008 breakthrough, "Esperanza." The album spent 78 weeks on Top Contemporary Jazz Albums, debuting at No. 3 and ultimately peaking at No. 2. "But I didn't respond to it. My objective is to evolve and grow. After my first album, I was feeling this and that's what I answered to."

What Spalding felt this time is the music she first gravitated to growing up: classical. The self-taught violinist and later graduate/faculty member of the Berklee College of Music spent 10 years with the Chamber Music Society of Oregon in her native Portland where she became concertmaster at 15. That training provides the foundation for the musical prodigy's modernized take on chamber music: accenting the intuitive spontaneity of improvisation with string trio arrangements combining elements of jazz, folk and world music.

Drummer Terri Lyne Carrington, pianist Leo Genovese, guitarist Ricardo Vogt and percussionist Quintino Cinalli are the core group backing Spalding, who co-produced the set with Gil Goldstein. Legendary vocalist Milton Nascimento also guests.

Spalding says, "I'm emulating something that chamber music used to do: Bring friends together to play music or listen to others play and enjoy the experience in an intimate setting."

How that will translate in today's marketplace is another story. Concord senior VP of Marketing/Label Manager-Jazz and Classics Group Mark Wexler, however, points out the basic element that initially attracted both regular and high-profile fans like David Letterman and President Barack Obama is still in place: Spalding's versatile talent.

"We're marketing the brand Esperanza," Wexler explains of the artist who has appeared in a Banana Republic campaign, won several jazz awards and performed at the White House in 2009, the Newport Jazz Festival and the 2010 BET Awards tribute to Prince at the request of the Purple One himself. "As people heard with her first album, she's a very talented woman who can play the bass and sing like a bird," Wexler continues. "Esperanza transcends what people think jazz is. She makes it accessible, and people -- both younger and more adult -- respond to the uniqueness of that."

Spalding switches to the electric bass for her upcoming third album, "Radio Music Society." Originally intended as the second half of a double-CD with "Chamber Music Society," the upbeat set is slated for spring 2011. "I wanted to find a way to incorporate jazz elements I find appealing into fun songs that could make it on the radio," Spalding says.

"I don't want to be pigeonholed," she adds. "My job is to do justice to the music that's speaking through me."

(Additional reporting from Jillian Mapes.)