Libertango is both an extension of the famed New Tango live recording Gary Burton and Astor Piazzolla collaborated on and a way for one of jazz's preeminent vibraphonists to continue tango explorations begun under the music's greatest modern architect. Burton assembles a killer band for Libertango's Piazzolla pieces, with guitarist Horacio Malvicino, violinist Fernando Suarez-Paz, and pianist Pablo Ziegler all coming from long tenures with Piazzolla's bands. What Burton does with the music will be unusual to tango enthusiasts and jazz fans alike. For the former group, he uses the vibraphone--with its hybrid percussive and harmonic properties--to sketch short improvisations and nuanced colorings inside the melodies. For jazz fans, Burton demonstrates how dynamically flexible tango formations are. They're intricately built and elaborately dramatic, but with Burton in the picture, the sonic dimensions widen and the vibes alternately mesh and stand out in the mix. He can comment on the melody, wind his own way through it, and solo all in a single piece, sounding perfectly adapted to his role. The Piazzolla tunes--including some of his most renowned ("Adios Nonino" and "Invierno Porteno")--come at a faster-than-normal clip, but in this way, they leap and hop. --Andrew Bartlett