Argentine tango lessons or Ballroom dancing lessons?

I would do Ballroom because its quite classy and probably could improve your skills and then move on to tango
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I think if you take ballroom dancing, you'll have a good foundation to learn other dances. The Argentine dancing lesson will teach you only one dance but the ballroom lessons will teach you many.
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Try both, see which one you like better. Some people do both and enjoy it. There is no need to take ballroom as a pre-requisite to argentine tango.

Conceptually, there is no difference between Argentine Tango and ballroom dances. They are all couple dances where one persom leads and the other person follows. However, very soon after the first few lessons you will see that the stance for Argentine Tango is very different than for ballroom. See which one do you like better. See if you don't find it confusing to do both.

I tried both at the same time, and I went on the path of competitive ballroom later on, and still very passionate about it. I dance Argentine on occasion too, but I don't work on developing it.

Also consider this: Ballroom dancing implies a lot of variety. You get to learn 12 or so dances, you don't get a chance to get bored.
Argentine tango = just one dance. (OK, OK, there is Milonga, there is Tango Waltz which are usually danced alongside with Argentine Tango, but still not as much variety.)
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