Newsom’s meandering songs are rooted in British folk tunes and Renaissance madrigals, but they can branch in unexpected directions. The singer’s current backup quintet is led by guitarist Ryan Francesconi, who also arranged the material on her vast new album, “Have One on Me.” Francesconi’s approach is to let Newsom be Newsom — whether playing harp or piano — and to underscore some moments with swells of sound. The drums would clatter and recede, the trombone bleat, the two violins screech briefly. On “Baby Birch,” Newsom’s anti-rock style was even buffeted by fleeting electric-guitar clangs.

In a 90-minute set that had space for only 11 songs, such old favorites as “Lily” and “The Book of Right-On” were given the same treatment as the new material. With her upper range less squeaky than it once was, Newsom sounded something like a mid-20th-century art-song performer — Lotte Lenya by way of Joni Mitchell. She’s also a jam band of a singer-songwriter, soloing on and on and rarely getting to the, or a, point.

Newsom is an original, and a skilled player. But the audience’s rapturous applause seemed to reward her as much for eccentricity as accomplishment.

– Mark Jenkins