Your concerns are in a very grey area.
Tango music/recordings as far as I understand are largely out of copyright
though I'm no expert. The record companies may say that a modern compilation
is protected though, maybe not the recording themselves but the work of preparation etc.
As far as ownership is concerned of a recording that has been downloaded
and temporarily stored to be played by a streaming website I have no idea;
it's more likely to be situation where policing possible retention is an impossibility.
I tend to take the view that anyone legitimately streaming audio, or even video,
knows the there is a likelihood of such retention, even if only by a minority.
Just keep it for personal use.
In the case of YouTube, most of the tango dance music played has been recorded
via the videocam so it's very poor quality and rarely would I take the trouble
to split it from the video. However it may be ok for an iPod or similar.
Incidentally for Jerry, Homer and Christina do seem to be dancing to Canaro,
which dchester said earlier is his preferred version and I hear why. If you want
a quality version, talk to Keith Elshaw at ToTango as he has restored
the Canaro rather than Lomuto.