If I understand correctly, by US law works of art are copyrighted 70 years after the authors' death. Seems that Argentinian law is similar: http://en.wikipedia.org/wiki/Argentine_copyright_law
So while you might be OK copyright-wise (but not codigos-wise!) with playing Gardel, most Golden Age era tangos are probably still copyrighted. However, rather than "Know and be able to prove that the music is now public domain" beforehand, I'd rather follow the opposite approach best summarized in this joke "I once prayed to God for a bike, but quickly found out he didn't work that way...so I stole a bike and prayed for his forgiveness". Unless you are making tons of money off the music (I'm talking using the music in a movie, TV ad or something like that), I wouldn't bother with copyright at all. I used to make videos for my town's public TV. The station's director said - "Theoretically, if you are using music in the clip, you should get the copyright owner's permission. Practically, even if you are violating the copyright, they can sue for the share of profits, but we are free, volunteer-based station anyway". Sergey _______________________________________________ Tango-L mailing list Tango-L@mit.edu http://mailman.mit.edu/mailman/listinfo/tango-l