Jacques d’Amboise, whose unique combination of classical elegance and all-American verve made him one of the premier male dancers at New York City Ballet, has died at 86. D’Amboise spent the last four and a half decades providing free dance classes to countless youngsters in New York and across the country through his National Dance Institute. Institute Director Ellen Weinstein says the dancer and teacher died on Sunday at his home from complications of a stroke. He was surrounded by his family. D’Amboise danced for 35 years at New York City Ballet, joining at 15 and leaving at almost 50, and founded his institute while still a dancer there.