BY GEORGE LOOMIS [NY Sun, 13 March 2006]

No one would argue that Scott Joplin's opera "Treemonisha" packs the dramatic punch of an opera byVerdi, who truly understood theater. The plot about former slaves who run a plantation abandoned by its white owners is slight, and the opera's message, that education is the key to black advancement, seems disconcertingly naive for an opera dating from 1911.