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.