Chamber Music is a collaboration between Ballake Sissoko, who plays the traditional kora, a lute-harp from Mali, and Vincent Segal, the French cellist who plays for the trip-hop band Bumcello.  It is also, quite simply, one of the most elegant and beautiful recordings of  world music  in recent years.  At a time when cross-cultural music has tended toward highly-caffeinated  electric pop and dance music, Sissoke and Segal remind us that there is room   and maybe even a need   for a quieter, more refined  world music.  Both musicians have displayed an aptitude for defying expectations   the list of trip-hop cellists is pretty short, after all.  And Ballake Sissoko has become a familiar name on the world music scene through his work with American blues legend Taj Mahal and Italian minimalist Ludovico Einaudi, among others.  But perhaps the combination of kora and cello works so well because there are no expectations for it.  The collaboration grew out of a personal friendship, and at no point was there an attempt to produce a record that would be slick and hip and commercial. Yet it has become one of Europe's most buzzed-about worldmusic recordings in the past year.  Chamber Music was recorded in the Moffou Studio, founded by the great Malian singer Salif Keita to provide a world-class environment for musicians wishing to record acoustic, perhaps even authentic,African music.  (Keita's own acoustic album, Moffou, was recorded there.)  The cello, of course, is not a traditional African instrument.  But Chamber Music, in its depth of feeling and variety of moods, is authentically African.  The kora may not appear in the duos, trios, or quartets of Beethoven, Schumann, or Brahms; but the obvious musical and personal connection between Ballake Sissoko and Vincent Segal also marks this as an authentic, if original, type of chamber music.