I crossed with two sentences:

 - Tango is a partner dance and social dance that originated in the
   1880s along to the Río de la Plata.
   
 - How to dance the Tango.

So, I got very confused because the definite article "the" is not used before proper nouns usually, and "Tango" is a proper noun. Thereby, why does one sentence use "the" and the other not? Is there any rule in this case?

I think that the same happens with the dance named Waltz.

Furthermore, why with some dances, it's not used any article, such as Ballet.

EDIT: It's been recommended this source:https://ell.stackexchange.com/questions/52263/the-top-levels-of-government-why-not-of-the-government. Nevertheless, I think this question is more related to the generic topic.