It all starts with the music. We dance to live music when we can, but more often to recorded music. At some events, the music program will be all blues, while in other places the music may range through a lot of genres and might not include any blues at all.
A little terminology: In the blues dance world, actual blues music is sometimes referred to as Traditional Blues, while any other music may be called Alternative Blues. A music program that includes non-blues might be described as Alt Blues or Fusion.
Bear in mind that outside the blues dance world Traditional Blues generally refers to older blues styles — generally rural styles that developed before World War II — while Alternative Blues doesn't mean anything at all. Fusion music would most often be understood to mean jazz incorporating influences from other genres, like Latin Jazz Fusion or Jazz Rock Fusion.