Michel Chion's third offering for Metamkine's series of 3" CDs, "Cinéma Pour l'Oreille," is also one of his most enigmatic compositions. Dix-Sept Minutes (Seventeen Minutes) is a work of musique concréte (fixed sounds as composition), but often appears to be a live electro-acoustic improvisation -- and a badly recorded one. It's all illusion. After a spoken presentation of the name of the artist and title of the piece (as if in concert), listeners are presented with a strange collage of disparate sounds, from battery-powered toys to vocal clips, all mixed over the background noise of equipment (film projector? tape deck?). The fact that the piece is dedicated to Lionel Marchetti makes things even more puzzling. Marchetti, who wrote a marvelous book about Chion's music, is one of the leading figures in live electro-acoustics. In fact, this piece often sounds like a cross between Marchetti's live work with Jerome Noetinger and his less-academic musique concréte (Knud, Un Nom de Serpent). So is this a tribute from the master to the disciple, an embrace of new forms of musique concréte or a skillful construction of false "real time"? In this reviewer's opinion, good avant-garde music should give birth to questions. Dix-Sept Minutes does.