Onstage spontaneity as metaphor for life

Rhiannon, yet another of San Francisco’s talented cadre of singers, doesn’t look like a revolutionary. When she first strolled onto the stage Thursday at the Vic in Santa Monica, her warm, even maternal appearance suggested an evening of quietly engaging music making.

Engaging it was. But it was a lot more, as Rhiannon began illuminating the links between jazz, voice, improvisation and life. She started her opening number with a breathtaking sequence of vocal sounds, singing percussive pops, clicks and swoops, adding soft-toned melodies, astonishing the full-house crowd as well as her accompanying musicians.

That was just the beginning of a set that embraced unique interpretations of Joni Mitchell’s “A Case of You” -- far surpassing, in imaginative qualities, other recent covers of the song -- and Lennon-McCartney’s “Blackbird”; several of Rhiannon’s own works, including a hilarious, rap-like romp through a piece describing, at breathless speed, the trials and tribulations of a busy workday morning; and several spontaneous improvisational passages with her players and the audience.

Rhiannon (who uses only the single, Celtic-derived name) did all this with pinpoint musicality, soaring invention and irresistible passion. A veteran of the women’s movement, her efforts were powerfully invested with the subtle, many-layered strengths of women’s culture, driven by her ensemble experiences with her own female ensemble, Alive!, and her work with Bobby McFerrin’s Voicestra.

When she wasn’t captivating her audience with her vocal energies, she was intimately reactive to the hard-swinging efforts of the talented young pianist Josh Nelson and the superb rhythm team of bassist Abraham Laboriel and drummer Alex Acuna.

In the study guide with “Flight,” her two-CD set on vocal improvisation, Rhiannon writes that “Improvisation is a gift, a necessity, a skill, a dance with the unknown.” That skill now needs revival and restoration, because, she notes, “When you improvise you become part of all that is alive.... “ In her quietly revolutionary fashion, Rhiannon displayed the fundamental, convincing reality of that thought.