What makes music "good"?

How much good music in a milonga is "enough"?

Enough that you can dance when opportunities arise.  A set is failing when a dancer is seeking another but one of them doesn't like the music and so can't dance.

What do you mean, "can't" dance? Don't you mean "won't". 

No, "can't".  Granted, this problem seems to afflict a vanishingly small minority.  Most people will dance anyway because for them the dance is movement, not music.  Movement, albeit to a beat with more or less any accompanying melody within the generically familiar sound of "tango". 

Often, the reason the music isn't "good enough" is  because it fails the "tried and tested" benchmark.  They are not the classic dance numbers, they are not well-loved.  

How do you know the music isn't good?  Doesn't it all just come down to personal preference? 

Of course individual taste in music is personal preference.  Taste is how you feel about something. That may be informed by education, by critical thought, but ultimately, we prefer colours, music, art, literature, environment, people because we just do, because of how we feel and who is to guess at the reasons for that. It isn't obvious.  Science is only just beginning to enter that territory.  

You can't dictate taste.  Some might try to make themselves like such and such.  As an eight or nine year old, I can remember thinking it would be convenient, appropriate, polite to like cucumber and eventually trained myself to tolerate it.  No sooner had I achieved this lofty goal than a neighbour served cucumber mousse at a barbecue and I was sick. It was a stark lesson that trying to coerce taste  in yourself or others is unlikely to end well.  At best you may end up feeling conflicted and uncomfortable. 

Sometimes of course, you grow out of some things and into others.  As a beginner I liked electrotango before I came to appreciate traditional tango dance music.  Some of us grow into coffee, olives and artichokes.  And children brought up in households where fish fingers, spaghetti hoops and soda is normal might never learn to like much more.  

So what makes something good? 

Good in the collective mind?  In art it's probably down to market value which means economics has utterly screwed aesthetic value in that area. 

Good in music?

Good in music is surely what individuals buy or what groups of people want to listen to, to dance to. And the longer those pieces of music are played and loved the better the piece might be, at least as judged by ordinary people rather than technical specialists.

So, good music in the milongas?

 Just what has been played, loved and danced for decades. The numbers you hear a lot, the numbers that inevitably get people on to the floor.