I don't know how many decades it was a duo dance? What is the name of the dance in which a group of two people hold each other's hands around the waist (the woman holding the man's shoulders)?

Waltz (Waltz), also known as round dance, a form of self-indulgent dance. The waltz, or round dance is also often referred to as the waltz.

The waltz is the earliest and most vital form of ballroom dancing, also known as round dancing. The word "waltz" originally comes from the Old German word Walzer, which means "rolling," "spinning," or "sliding. ".

After the waltz according to the speed of differentiation into two kinds of fast and slow, people call the fast waltz Vienna waltz, and not crowned with the word "Vienna" that is, the slow waltz, which is evolved from the Vienna waltz. As a three-step waltz, its basic steps for a beat jump one step, three beats per bar jump three steps, but there is also a bar jump two or four specific steps.

The two types of waltzes, fast and slow, are mainly rotating, hence the name "round dance". Waltz because of the slow speed, in addition to more rotation, but also evolved more complex and colorful dance steps, many of which are in step with the tango, foxtrot and quick-step dance steps of the same name are basically the same, just different rhythms and styles. Plus the four major skills in the waltz to get a comprehensive and full embodiment, so it is listed as the first dance to learn the GB dance.

The waltz steps in the slow speed of the three-beat dance in the smooth running, due to the obvious lifting and lowering of the action, such as a continuous wave, coupled with the gentle and dexterous tilting, swinging, reversing and rotating movements and a variety of beautiful modeling, so that it has a dignified and elegant, elegant and generous, but also gorgeous and colorful, elegant and immortal unique charm. Therefore, it enjoys the reputation of "after the dance".