Tues. Feb. 27

    Look, we hear the word "extreme" attached to anything nowadays and we cringe. Extreme Home Makeover. Extreme sports. Extreme nachos. The word has truly lost its punch except ... maybe in the case of "Extreme Spirituals," the new CD by avant-garde Boston band Birdsongs of the Mesozoic and bass baritone singer Oral Moses. These songs are not straight-up by any means. The boys in Birdsongs claim on the jacket cover that they bring these "centuries old songs into the 21st century." The music both complements and contrasts with Moses's stately vocals, sometimes adding an ethereal aspect. (Rest assured: Birdsongs is still quirky, but has put aside their penchant for dissonance on this one.) Moses says, "These aren't just African-American songs - they're American songs." Hear "A Little More Faith in Jesus," "Nobody Knows the Trouble I See'' and "Amen" in an entirely different context. Says saxophonist Ken Field: "I think we do what we do, but we do it with the context in mind. When you have a lead voice, you have to scale back a little bit and take some of the attention away from what the instruments are doing. and Oral's got such a big booming voice. The four of us are not particularly religious people. Are we spiritual? I would hope that we are, which means to me that your focus is not 100 percent on material things. We think about things that are not material things and sometimes music is a spiritual experience.'' Moses and the four Birdsong guys will be at Berklee Performance Center Tues. Feb. 27 at 8:15 p.m. Tickets: $5.

136 Massachusetts Ave., 617-747-2261 berkleebpc.com