Since 1990, when he played bass on albums by elder greats Roy Hargrove and Wallace Roney, Philadelphia's leading bass man Christian McBride has been considered one of the finest craftsmen in jazz, whether jamming, collaborating, or composing.

In 1998, McBride got the opportunity of a lifetime: a commission from Maine's Portland Arts Society to compose a piece for Black History Month. The work, which is titled The Movement Revisited, concerns itself with African American themes and includes a choir. It comes to Philadelphia for the first time this weekend.

So he composes choral works now?

"I still don't have much experience," he says, holding back a laugh.

Originally written for his quartet, a small gospel choir, and several narrative voices, The Movement Revisited now has an additional chapter ("Apotheosis: November 4, 2008," a tribute to the presidency of Barack Obama) that joins existing segments dedicated to civil-rights icons Rosa Parks, the Rev. Dr. Martin Luther King Jr., Malcolm X, and Muhammad Ali. McBride's majestic music seeks to replicate the scope of their achievements, with an 18-piece ensemble, a large choir (the Philadelphia Heritage Chorale), and four narrators, including Philadelphia poet Sonia Sanchez.

"My biggest challenges were to just get out of my own way," McBride says. "That, and to try to enhance the spirit" of each icon's familiar words. McBride's music is peaceful and soft for Parks; loud, brash, and bold for Ali; serene and Coltranelike for Malcolm X; slow and grand for King.

"I don't want to predict anything, but the magnitude of the piece - why it was written, what it was about - I can't imagine I'll ever write something as monumental on this scale again," he says. "I do get overwhelmed playing it, and every time I do, it feels new. Sometimes, I play this piece and still go, 'Wow, did I really write this?' "

Christian McBride's "The Movement Revisited" plays at 8 p.m. Saturday at the Merriam Theater, 250 S. Broad St. Tickets: $29-$72. Information: 215-893-1999,