Traditional Irish dancing has been around for hundreds of years. People danced in kitchens, in barns, and at country crossroads where families would gather on summer evenings to play music and dance until late.
The dancers wear special shoes. 'Soft shoes' are like ballet slippers and let the dancer leap silently. 'Hard shoes' have a hard tip and heel and click loudly on the floor, almost like tap dancing. A fast hornpipe in hard shoes sounds like a drum solo.
Why are the arms held still? Nobody is totally sure. Some say it was to make the dance look graceful in cramped kitchens. Some say it was a way of dancing with great control. Either way, it is part of what makes Irish dancing instantly recognisable.
In 1994, a seven-minute Irish-dance show called Riverdance was performed during a break at the Eurovision Song Contest. The audience cheered for so long that Riverdance grew into a full show, then a world tour, and Irish dancing exploded around the planet. Today, Irish dance schools exist on every continent (except Antarctica).