Reading some interesting ideas about grand endings... yes! that makes sense, and it's nice to have a good ending. But if you watch BsAs tango – check out some of the videos around – grand endings don't always feature. Essential in stage tango, of course, which is danced to be watched. I think what's essential in BsAs tango is connection*: you might have a great connection for a few moments of a tango, for a whole tango if you're lucky, or in some mythic, wonderful world, for a whole tanda.
One neat video somewhere (tangoandchaos probably, but I can't remember where) the couple fit some lovely moves to the music early on, then finish dancing before the end of the music. Whatever feels right: they'd had their moment. You've had a lovely intimate conversation: no need to ruin it by going out of your way to shout a platitude. & grand endings aren't inevitable in the music either: the music often ends in a bit of a throwaway fashion.
'It’s a song with a sentimental voice…
its beat is the rhythm of my city.
It's not vulgar,
and it's not pretentious.
It’s tango... and nothing more'
(From Rick McGarrey's translation of Una Emoción, tangoandchaos.)
* Connection with a partner AND with the music.
PS. Found it, the tango where the couple finish dancing before the end of the music. It's here. And that whole page on 'entrega' - getting lost - is very interesting.