The Kronos Quartet has achieved a lot in its time, but in Nuevo has managed a true milestone in a very auspicious career. The quartet has taken the music of Mexican composers, from the classicalpiece in collaboration with the band), and made them into a wonderful whole. Kudos also go to the production, which makes the opener, El Sinaloense, sound like a scratchy old 78 record at excessive volume (the remix of the piece that closes the album is a different kettle of fish altogether). Many of the tracks bring in other players, on instruments ranging from the mysterious plasmaht to the musical leaf, along with more recognizable things, like marimba. The result captures some of the many spirits of Mexico, from the chaos and celebration on K'in Sventa Ch'ul Me'tik Kwadulupe through the simple, elegant, and often playful joy of Chavosuite, where toys are played, to the daring long journey of 12/12. While the Kronos Quartet has long since blurred musical boundaries into oblivion, this might be the biggest step the ensemble has taken yet -- and with it comes a complete, unreserved triumph.