I always tell my students that if a deaf person watches you dance, that person should be able to tell which dance you are doing by the way you move. The music is only one of many things that make a dance unique. Each dance has a special sound, character, feeling, movement and look. Just because you are moving around the floor while Waltz music is playing, doesn't mean you are actually dancing the Waltz.
Ballroom Dancing has specific requirements for each dance. These requirements are what make each of the dances have a unique sound, look and feel. No two dances look or feel the same. In Ballroom Dancing, you may have the same elements or patterns in more than one dance, but they don't look or feel the same because of the way they are danced. The character of the dance is defined by the actions happening between the steps. There is so much more going on in Ballroom Dancing besides patterns.
The patterns of each dance are designed for music of a specific speed. That is why Slow Waltz and Viennese Waltz have different patterns. Viennese Waltz's music is about twice as fast as Slow Waltz. Slow Waltz has a "rise and fall" body action. Viennese Waltz does not have "rise and fall" because there is not enough time. The patterns are flat and rotating.
Footwork is another aspect of Ballroom Dancing that creates unique body actions, movement and feeling. In Smooth/Standard dancing, "heel steps" are executed so as to be able to travel around the dance floor. In Rhythm/Latin dancing, "ball flat steps" are executed to accommodate "Cuban/Latin motion" (hip action). Footwork (heel, ball, flat) is responsible for the up and down swooping action of Slow Waltz and the footwork of "heel, flat" creates the smooth, level and even movement of Slow Foxtrot.
The definition of the dancers' legs and bodies has an affect on the character of the dances. The Smooth/Standard dancers' legs are defined as from the hip sockets to the floor. The body is defined as from the hip sockets and up. The Rhythm/Latin dancers' legs are defined as from the bottom of the rib cage to the floor. The body is defined as from the bottom of the rib cage and up.
The leg actions of the dancer create another aspect to further determine the uniqueness of each dance. The continuous soft knees of the Slow Foxtrot dancer creates an even, smooth and level movement. The bending and straightening of the Slow Waltz dancers' legs, helps develop the up and down swooping action.
The power of the movement also has an influence on the character of each dance. Slow Waltz has a "power and glide" feeling. Slow Foxtrot has a very "even continuous" feeling of power. American Style Tango has a very "strong, powerful, pulsing" feeling.
The partnership contributes to the feeling of each dance too. The "Smooth/Standard" frame ("Y" shape) creates a very different feeling than the "Rhythm/Latin" frame ("A" shape). The "Y" shape allows for the partnership to travel around the floor and the "A" shape accommodates the knee action required for "Cuban/Latin" motion.
Head position and body posture affects the feeling of each of the dances. Smooth/Standard dancers have a slightly backward feeling while the Rhythm/Latin dancer has a slightly forward feeling. The body weight of the Smooth/Standard dancer feels like it is slightly on the heel of the feet. The body weight of the Rhythm/Latin dancer is slightly on the ball of the feet.
The Rhythm/Latin dances have basically the same footwork and body action. The footwork is "Ball Flat" and the body action is "Cuban/Latin" motion. The biggest influence on the characteristic of the Rhythm/Latin dances is the rhythm of the music and the speed of movement.
As you can see from the above, there are many elements that affect the character of each dance that makes it unique. These elements are not generally taught in Ballroom Group Classes. Most of these elements are learned through private lessons because it is more about feeling instead of geometry.
The trap that many students fall into is that they try to learn to Ballroom Dance through Group Lessons only. This results in the student learning just foot patterns not the actions that happen between the steps. The students become what I call "Pattern Dancers". They can walk through the dances' patterns, but all of the dances look and feel the same. No matter how many new patterns you learn eventually they will all feel the same. Ballroom Dancing is all about "feeling" not mechanics.
Private lessons are the most effective way to learn the "feeling" of each dance. I recommend to my students to learn the patterns in the Group Classes and then learn to dance them in private lessons.