With no orchestra as cover and no distance at all from onlookers, the most striking thing about a dance rehearsal with the Houston Ballet is the noise.

Onomatopoeia reigns as dancers pound their way across the floor – accompanied by the occasional grunt and heavy puff of breath. If this was a children’s book, the words BANG, THUD and SCREECH would be in all caps right next to the illustrations. They are, in scientific terms, working their tails off.

Three casts worth of dancers (some are in more than one cast and switching roles from one to the next) are running their parts this week for the upcoming production of Cinderella with choreography by Houston Ballet Artistic Director Stanton Welch. Fine tuning to an nth degree, they are working through any last-minute bobbles, sorting them out in the rehearsal room and far away from the paying audience.

A few members of the corps veer into each other in one of those sweeping runs off stage. The ballet masters stop action to tell another group that they’ve probably just danced through the now invisible furniture that isn’t in the spacious rehearsal room but will be onstage. “Where is your dress?” a ballet master asks one of the dancers. It hadn’t been laid out in its proper place.

A stepsister runs up to a full-length framed mirror and attempts to flip off the long antique-looking scarf hanging on it. Instead the fabric catches on the frame, pulling the whole thing forward toward the dancer. The pianist stops playing. People laugh but just as quickly discuss how this can be resolved. When they restart, the sequence proceeds without a hitch.

Even without their costumes – although dancers do don skeleton masks for one dance – the lines of the story and their athleticism, grace and beauty come through strongly.

They rehearse for an hour, clicking off calories like a Geiger counter at an uranium mine, take a ten-minute break and dance again.

All we have to do is watch and be amazed.