I have bumped into the article: "Tango: Theme of Class and Nation" http://links.jstor.org/sici?sici=0014-1836%28197605%2920%3A2%3C273%3ATTOCAN% 3E2.0.CO%3B2-3&size=LARGE published in "Ethnomusicology" in May, 1976 ! You can only see the fist page. But it clearly states that tango was still very popular in Argentina. Igor