Astor Piazzolla, brilliant, iconoclastic tango musician and composer, has become a national hero in Argentina and a cult figure for classical and jazz lovers worldwide, but only after a lifetime of controversy and struggle.The outspoken, headstrong Piazzolla told his story to journalist and longtime fan Natalio Gorin in the spring of 1990 in a series of frank interviews.Among the firsthand observations of others who knew Piazzolla well are those of...