Cris Williamson returned to the town where she once lived and played for a triumphant concert at Constitution Hall Saturday night. Williamson's new work is far more ambitious than the gentle spirituals that made her a feminist hero: Employing synthesizer and rock 'n' roll guitar, her new songs crackled with a challenge to her old fans as her career moved to a new plateau. c

Williamson opened the show with a five-song medley from the album that won her a cult following, "The Changer and the Changed." The lush, hymnal harmonies of those songs contrasted sharply with the brash, gleeful sounds off six rock 'n' roll oldies later on.

Even more impressive was her dark, brooding vocal that made "Strange Paradise" sound like a very uncomfortable utopia. Her music for "Twisted Love" was as alluring and painful a the theme of destructive romance.

Williamson is a big vague and cliched as a lyricist, but she is a gifted composer and a pleasurable singer. Her voice slid gracefully through her skipping melodies and swelled with emotion on the sustained notes. More importantly, her voice was pushed by the determination of optimism even as it was shadowed by sadness. Unfortunately, the folk-rock trio that backed her Saturday was too sluggish to keep up with her adventurous music.