The goal of ballroom dancing is to create that unique four-legged feeling that can only be developed through the partnership of the dancers. It is that look and feel of being one on the dance floor. "Four-legged feelings" are feelings that can only be achieved when you truly become a two-headed four-legged animal.
When we first start to learn to dance, we learn our own foot steps, then we learn pattern elements and then finally we learn the pattern. Unfortunately, this is where many dancers stop. They don't go on and learn the true feeling of partnership dancing, and that unique "four-legged feeling" that produces that incredible "oneness" on the dance floor.
Dancers that don't grow beyond learning foot steps, I call "pattern dancers". Basically, each side of the partnership dances their own part with some connection in order to be able to move together. This is not wrong, but there is so much more beyond this stage of dancing. Typically, "pattern dancers" learn their own parts then they dance those parts together with their partners. The part that each partner practices by themselves feels the same as when they dance it with a partner. These are not "four-legged feelings". A "four-legged feeling" is that unique feeling created by being one in the partnership. The dancer cannot create this "four-feeling" by practicing alone. Only the merging of the two partners creates the true "four-legged feeling".
Dancers that fall into the "pattern dancer" trap, usually have an endless thirst for more and more patterns. This is because after a while all the patterns feel the same. They seem mechanical instead of having feelings. Knowing more patterns doesn't solve this problem. Dancers that have progressed beyond patterns, try to develop more feeling from the patterns they already know. As the dancers continue to grow, they discover that a single pattern can generate many different "four-legged feelings" depending on the interaction of each side of the two-headed four-legged animal. These "four-legged" feelings cannot be developed by you as a two-legged animal. You can practice your part alone but realize that when you dance with a partner the feeling will be different.
Typically, "pattern dancers" like fast music and dancers with "four-legged feelings" like slow music. I always tell my students that dancing is what happens between the steps. "Pattern dancers" don't have much going on between the steps so it is hard for them to dance to slow music. "Four-legged dancers" like slow music because that allows them more time between the steps to be able to develop the "four-legged feelings".
How do I progress from a "pattern dancer" to a "four-legged dancer"? Basically connection to your partner is the first step. The connection needs to be as light as possible, yet you must still be able to feel your partner. The lady must be able to feel what to do, one step at a time. The lady participates in developing the feeling of every step. The man must know the ladies part as well as he knows his own. He must know what the lady is supposed to do and lead accordingly. The man must lead in such a manner that the lady feels very natural in her movements. The man may have to do some seeming unnatural movements to create natural movements in the lady. The man may dance very specific parts of the ladies body (using invisible connections) depending on what he is trying to get her to do. The dancer moving forward is in the best position to supply power. One of the responsibilities of the man is to generate the power when moving forward and to start and direct the power of the lady when she is moving forward. These are just a few items that contribute to "four-legged feelings".
The dancing that creates the "four-legged feelings" cannot be seen visually by watching. You can see that the quality of the dancing is very good, but you can't see what is developing it. This is the kind of thing that you learn in a private lesson. Even in a private lesson it is very hard to verbalize and is better taught by feeling it from your instructor.
There is no single "four-legged feeling". "Four-legged feelings" are unlimited. Your dancing will never get old or repetitious as long as there are "four-legged feelings" in your movements.