Astor Piazzolla is Argentina’s most famous musical name—the man who has almost single-handedly brought the passion, thrill, and beauty of the tango to a worldwide audience. Would the composer and bandoneon player have been able to achieve this without years of studying in Paris with the great Nadia Boulanger? Maybe, but Boulanger clearly instilled in Piazzolla a European sensibility for orchestration and arrangement while encouraging him to preserve the essence of his homeland’s musical traditions. The resulting, exquisitely orchestrated works that flowed from his pen in the following years include 1974’s “Libertango” and “Milonga del angel.” In this 1997 Grammy-winning album, Yo-Yo Ma and friends perform arrangements of these two pieces alongside other, lesser-known gems such as “Mumuki” and “Fugata.”