Some content in this article is derived from information featured in Harry Potter and the Cursed Child, and, as such, spoilers will be present.
The tango was a dance characterised by the partners maintaining close body proximity throughout, and an alternating pace of slow, flowing movements interspersed with faster, sharper ones. It originated in the River Plate region that formed the natural border between the countries of Argentina and Uruguay.
The elderly witches and wizards who resided at St Oswald's Home for Old Witches and Wizards no longer had to use magic for practical, day-to-day purposes. Thus, they used it toward a variety of whimsical ends, including making the male nurses who worked at the care home do the tango.