Released in 2006, Spalding's debut album, Junjo, was an enchanting group effort on which Spalding plays bass and vocalizes wordlessly with Cuban pianist Aruan Ortiz and drummer Francisco Mela. She covered a lot more ground on her well-received 2008 sequel, Esperanza, on which she sings in English, Spanish and Portuguese.

Last year's Chamber Music Society is Spalding's most recent project. A Manhattan performance in the fall began with the bassist relaxing in an armchair at the corner of the stage, sipping a glass of wine and savoring the sound of the string trio she soon joins, along with a pianist and drummer. Fusion at its finest, Chamber Music Society blends Spalding's classical background with flighty improvised vocal excursions, solid original balladry such as "Apple Blossom" and a moving take on Dimitri Tiompkin's "Wild Is the Wind."

Spalding views her Grammy nomination as an unexpected preview of what will be her next project. Radio Music Society, she explains, will focus on "the part of me that likes to get in the car on a sunny day and sing along to something that has nothing to do with hipness or a dead idiom," meaning jazz. And if on Sunday she beats out a bunch of pop stars for a Grammy, all the better.

"At least when my next record comes out it won't be like, 'Wait! You've betrayed us!' "