Purists, whether they specialize in classical music or tango, have sometimes scoffed at the efforts of Ariel RamÃrez to bring Argentine folk music to the widest possible public. Yet since the 1960s, RamÃrez has been tremendously successful as a folk music crossover evangelist, particularly thanks to his best-selling Misa Criolla. At age 19, RamÃrez got a job teaching in the mountains of Argentina, where he was first introduced to his nation's folklore. He spent three years absorbing the music of the Indians, gauchos, and creoles. Later, in his twenties, RamÃrez studied mu...