A dance that was developed in Argentina, where legend has it that gauchos, having ridden all day, walked with flexed knees. Of a night they would go to crowded night clubs and ask ladies to dance but since the gaucho hadn’t showered, the lady would dance in the crook of the man’s right arm, holding her head back. There is no rise and fall in the steps. This should be a very level, flat dance. The legs are therefore always slightly flexed (i.e. the knees should be slightly bent at all times).

The Tango is a very emotional dance and this should be conveyed. Tango dancers must strive to make a strong connection with the music as well as their audience. There must be lots of clipped movements and the action must always be staccato. One teacher suggests that the movements are very “panther-like.” Work on sharp head turning and stops. The hold is different in the tango. The man’s left arm is more towards head level. The general hold is far more compact and the couple are much tighter together.

More information:
https://en.wikipedia.org/wiki/Tango_(ballroom)