What is the meaning of Tango? And what does it have to do with the black moon?

Like the black moon, Tango too can be explained in astronomical terms: It’s all about the comfort of regular motion based on gravity, about circular movements, spinning in orbit and about heavenly bodies dancing around each other.
  We believe that in order to be truly happy, you need to know how to be truly sad.
  The Finnish word for this cosmic feeling is ‘Alakulo’, very roughly translated as ‘melancholy’, but of course much darker and deeper.
  Alakulo is also the name of our Tango, because for any Finnish artist Alakulo is the ultimate creative state of mind and soul. Experiencing this sombre flow is like the feeling of a black moon rising.
  We believe that Tango belongs to the dark. Forget dancing in the moonlight and prepare for a black moon rising, for stray cats and creatures of the night.