The M-Base group in Brooklyn, working with both jazz and pop forms, makes music that at first sounds like funk from the 1970s. Like the music played by Mr. Marsalis (and his brother Wynton) the music made by M-Base - Steve Coleman, with Greg Osby, Cassandra Wilson and Geri Allen – is, at its best, filled with subtle ideas working behind the mask of popular music. In Mr. Coleman's group a singer is supported by an electric bass, guitar, drums and electric keyboards, a shiny musical mix that has familiar rock and funk references; yet, because of all its rhythmic and metric manipulations, sounds new.