Gravity-defying voice, career lift off

“I feel very connected to this specific group of guys,’’ says Stevens, 27, who performs Monday at Club Passim with her working quartet featuring bassist Chris Tordini, Liam Robinson on accordion and keyboards, and Jordan Perlson on drums and percussion. The musicians all contribute vocals, too, adding earthy textures to Stevens’s insouciantly gravity-defying soprano acrobatics.

“They’ve stuck with me, they’re dear friends, and we’ve developed a sound and approach in the way that we work through the music,’’ Stevens continues. “I’ll write a song and flesh everything out, the guitar and vocal parts. But they expressed the desire not to have any sheet music, so I never have to write anything out. They have all the music inside of them.’’

Whether or not Stevens is a jazz singer, the jazz world has been eager to embrace her. Peers like Kate McGarry and Kurt Elling have hailed her as one of the most original young vocalists on the scene, while heavyweight players like pianists Brad Mehldau and Taylor Eigsti, trumpeter Jeremy Pelt, and drummer Eric Harland have recruited her for projects. Whatever context she’s working in, Stevens makes a vivid and enduring first impression.

“The first time I saw Becca perform I was completely in awe of her voice and intensity, the level of emotion and intellect,’’ says vocalist Gretchen Parlato, who contributes to one track on “Weightless’’ and collaborates with Stevens in the a cappella trio Tillery with Rebecca Martin. “She’s a ridiculous singer and songwriter, and whether it’s in a rehearsal or performance I have a jaw-dropping, goose-bump reaction every time I hear her.’’

The release of “Weightless’’ last April on Sunnyside, a follow-up to her impressive self-produced 2008 debut “Tea Bye Sea,’’ has provided a similarly revelatory calling card for Stevens. In many circles she’s still best known as the lead singer for saxophonist Travis Sullivan’s big band Bjorkestra, a group she connected with as an undergrad at the New School.