Cynics might look at Hannibal Lokumbe's 1990 African Portraits as a crowd-stirring, politically correct musical Roots for the 90s. No one, however, can dispute the earnestness of this ambitious 45-minute work by the multifaceted composer previously known as Hannibal Peterson (his name was changed last month after a tribal ceremony). Commissioned by the Baltimore Symphony Orchestra and the American Composers Orchestra, African Portraits aims to be a grand, hortatory treatment of African-American history. Based on a poem Lokumbe wrote after a fateful sojourn in Nairobi in the 70s, it successfully evokes the lush jungles, red desert, and agonized people of Africa. But heartfelt moments aside, it's ultimately a cleverly crafted yet bewildering mishmash of predictable idioms. Lokumbe, who decided to become a musician at 13 after hearing John Coltrane and has played trumpet with the likes of Gil Evans and Pharoah Sanders, mingles blues and gospel numbers with jazz tunes sung in English and Mandingo. Despite the presence of a griot playing on a kora (a 21-string plucked lute), the work lacks structural cohesion, seeming at times like a medley of rousing choral highlights that gratuitously calls for a large orchestra. Among the featured performers at this local premiere are Alhaji Bunka Susso as the griot and the Hannibal Lokumbe Quartet; the choirs of Kennedy-King College and Morgan State University also participate. The performances, under Daniel Barenboim's direction, are to be recorded for release by Teldec. A preconcert discussion begins an hour before each show. Friday and Saturday, 8 PM, and Tuesday, 7:30 PM, Orchestra Hall, 220 S. Michigan; 435-6666.