Horses can actually be incredibly nimble! Watching most any sort of working horse, particularly roping/cutting horses and western discipline with their turn-on-a-dime twists and circles really show how fast even whole-body movements can be, but of course looking at dressage and horses at liberty shows are great inspiration for what centaur dancing can look like!

A lot of what we perceive as fairly clumsy movements from horses in acts/shows are because they are just doing a trained movement, so the movement is going to depend on how much the trainer was able to convey to the horse in training, how much the horse is motivated to do the thing in the moment, and a million other horse thoughts going on at the time of the trainer/rider asking for the behavior. So compared to a trained dancer who knows exactly what they are trying to achieve and has potentially trained to push the limitations of their own bodies, the possibilities for centaur dancing are a huge extension on any movement you can imagine and see a horse performing naturally!
I think all kinds of dances would work no issue, though they would need a lot more room than your average human dance floor!

I think a lot of the dancing would involve a lot of spinning and tight circles, showing off foot-coordination and fancy turns- particularly when done with a partner! Another important aspect would be percussion rhythms ‘played’ with the hooves as they move, particularly for solo performances, but a fun layer to add to any dance! (add bells and noisemakers to the hooves for extra flair!)

and a preview of another ask, as well as my favorite idea for the casual centaur dancing pair is simple fancy pacing in coordination with a partner, generally in some form of graceful swooping pattern that includes other pairs if you really want to make it a party!

The possibilities are endless! Even something like the rearing wild stallions do at each other could be imagined as a cool dance with a bit of coordination!