Tango embodies the traditional roles of the man as a leader and the woman as a follower. Advanced tango dancer switch their roles and it is not unusual when the woman takes the lead.
Most couples dance tango with their significant ones, but for those who are still single, tango is a great way to meet new people.
A quick search on free online dating websites like plentyoffish.com and okcupid.com reveals that there are people who are into Tango and are both available and looking for dating/dance partners.
If you want to find tango partners just use the advanced search in your dating site and type in tango in interests or keywords section.
From over thousands of profiles worldwide, there must be someone near you. Good luck.