The following indicates some of the basic differences between just a few of the swing dances. Please note that these are just some of the most obvious differences. There may be other differences. Also, there are many similarities which are not included here. The main purpose for including the following information is to help new people try to identify some of the swing dances.
East Coast Swing
Uses mostly 6 beat and some 8 beat Step Patterns. In Open Position, the follower normally does a [rock step] on counts [1 2] and may or may not move toward the Leader on counts [3 & 4]. The basic 6 beat Rhythm Units are EVEN, ODD, ODD. The basic 8 beat Rhythm Units being EVEN, ODD, EVEN, ODD.
West Coast Swing
Uses 6 and 8 beat Step Patterns. In Open Position the Follower normally walks directly toward the Leader on counts [1 2]. In Closed Position, there are two different basic styles. In the first style, the Follower does a [rock step] on counts [1 2]. In the second style the Follower walks forward away from the leader on counts [1 2]. The basic 6 beat Rhythm Units are EVEN, ODD, ODD. The basic 8 beat Rhythm Units being EVEN, ODD, EVEN, ODD.
This is an advanced form of west coast swing dance that allows the leader or follower to extend patterns at will with their own interpretive styling to the music. The term Hijacking is sometimes used when the follower takes control throughout their interpretive extension of a step pattern. Leaders should use a feather light lead to give the follower as much freedom as possible.
Get Down Swing
This is a funky new form of swing dance created by H. Leon Raper. Its roots come from the Charleston and St. Louis Shag (AKA: Kenny Shag or Speed Shag). The uniqueness of Get Down Swing comes from a special funky new styling applied to the Odd Rhythm Units of the other swing dances such as West Coast Swing, Lindy Hop, East Coast Swing, etc.
The original Lindy Hop came from the Charleston which was an 8 beat dance in its basic form. In the early 1930’s dancers found that step patterns from the 6 beat dances such as Shag could be integrated very easily with the 8 beat step patterns of Lindy Hop. This resulted in the new Lindy Hop you see in movies such as “A Day At The Races” (1937) with the Marks Brothers, and “Helzapoppin” (1941) with Frankie Manning.
A great deal of Lindy Hop can be accomplished using only 8 beat Step Patterns without ever doing a 6 beat Step Pattern. I do not teach 6 beat step patterns in my basic Lindy Hop Classes. I teach the original Lindy Hop.
In Open Position, depending on the particular Step Pattern, the Follower may either do a [rock step] on counts [1 2] or may stay out on count  and walk directly toward the Leader on count . In Closed Position, the Follower will almost always do a [rock step] on counts [1 2]. The basic 6 beat Rhythm Units are EVEN, ODD, ODD. The basic 8 beat Rhythm Units being EVEN, ODD, EVEN, ODD.
Uses mostly 6 beat with few 8 beat step patterns. Most dance instructors today are teaching a [Rock Step] [Kick Step] [Kick Step] version of East Coast Swing using counts [1 2] [3 4] [5 6]. When someone asks me for Retro Swing lessons, I teach Lindy Hop since its is a much more advanced form of dance than East Coast Swing forms. For further definitions see Elements of Music or HELP
Is a form of dance very similar to east coast swing, but normally very energetic, with lots of kicking - very similar to a good aerobic workout. The basic 6 beat Rhythm Units are EVEN, ODD, ODD. The basic 8 beat Rhythm Units being EVEN, ODD, EVEN, ODD.
Balboa is basically an 8 beat dance with its basic Rhythm Units being EVEN, ODD, EVEN, ODD. The ODD Rhythm Units are danced as either a Single Rhythm Unit [X /] or a Delayed Single Rhythm Unit [/ X]. Maxie Lee Dorf and Willie Desatoff used both type ODD Rhythm Units during the same dance Maxie and Willie are considered by many to be the greatest Balboa dancers there ever was. Balboa is an offshoot of the original Charleston style of dancing.
More Balboa Information:
This can be very confusing to newcomers since there are several different types of Shag.
Charlie Womble & Jackie McGee Style: Uses both 6 and 8 beat step patterns with a lot of styling action in the lower body. If you see someone doing West Coast Swing with rubber legs and tight footwork, you are probably seeing this style of dancing. This is also referred to by many as Carolina Shag.
St. Louis Shag (Kenny Wetzel Style): Is an 8 beat style of Shag which can be done at very high speeds. This is also sometimes referred to as Speed Shag. It feels best done at over 200 beats per minute and attainable speeds of over 300 beats per minute. This style of Shag is an offshoot of the original Charleston style of dancing. The basic patterns of this form of Shag are close together with no basic step patterns such as you see in West Coast Swing. Also see St Louis Shag, Updating The Count.
Early 1930’s Shag: This is a 6 beat form of dancing that would be similar to the 6 beat forms of Retro Swing we see today using [Rock Step] [Kick Step] [Kick Step] types of step patterns. Arthur Murray put out a good training film in 1935 presenting this form of Shag.
Is definitely “NOT a Swing Dance” – and never was!!! This is not meant to be negative about Pony Swing - it is a fine dance in its proper category which is Pony Swing.
Competition Categories: It is also the opinion of this writer that for competition dancing, only categories of Swing Dance with similar characteristics should be allowed to compete against each other except possibly in the Cabaret Division. That does not mean that the competitors should be prevented from using material from other categories, but it does mean that the majority of their material should be limited to the category in which they are competing.
Ballroom Jive vs Complex Swing Dances: It is a mystery to those in the Swing Dance community why Jive is still included in much of the National and International Ballroom Dance Competition instead of the much more complex swing dances such as Lindy Hop and West Coast Swing. I only hope that as dance is included in the Olympics that the more complex swing dances will be included instead of Jive.