The other sound comes from Gail and Tommy Davis, a couple for more than 40 years who hold each other so gently, gingerly and beautifully, they seem to merge as one moving machine.

"One two three, one two three, one two," then again and again.

What could they be doing. The eight beats?

They are teaching the shag.

The shag, in this YMCA in a room next to the sweating people who want to live forever through exercise, is a way of life.

It is a noun. The shag.

A verb. He shagged.

A holy cause. To shag.

The shag has roots so deep in area brains it is a mighty tree. It withstands hurricanes, floods and droughts. It endures.

The shag has been the state dance since 1984. The shag is the dance at the Grand Strand -- more specifically, Ocean Drive Beach north of Myrtle Beach -- since after World War II, at places such as the Pavilion, Fat Harold's, the Spanish Galleon, Ducks, Ducks II and The Pad. All of these places held a million memories for Carolinians who went to the beach during the summer.

Beach Music is the anthem -- the sound and those songs that came from black musicians in the 1940s, '50s and '60s and changed the leisure lives of generations.

Tommy and Gail Davis, the teachers, took shag lessons together more than 20 years ago as a couple and never looked back.

"I love the shag," Gail Davis said.

She said "love" like people say they love kids and grandchildren.

I find out the Rock Hill Shag Club, the local club the Davises belong to, is second-oldest in the state, dating back to 1981. Its maestro, master, now the guy in charge of a national group called the Society of Stranders that gathers each year at the beach in a group so huge it takes a group of nightclubs to make room for all the shaggers, is a Rock Hill guy named Ron Whisenant. Whisenant has been shagging for 52 years. He takes any and all opportunities to talk the shag, dance the shag, preach the shag.

"It's a lifestyle, the shag," Whisenant said.

But these people are long-time shaggers. What about these others taking lessons? I wrote earlier this year about why people take pole-dancing classes -- exercise -- and why people take belly dancing classes -- intrigue.

These people taking the shag want to dance. To dance when you live in South Carolina is to shag. Simple.

Wylene Roddey of Chester and Jonathan Bass of Fort Mill are getting married next year. Their families have shagged for two generations. They are taking the class so they can dance the shag at their own wedding.

"I have to shag," Roddey said.

There is no doubt it's as important as buying a house.

A young guy, 23, named Cliff Goolsby takes the lessons with his girlfriend.

"I'm from South Carolina, it's the state dance, I need to be able to shag," Goolsby said. He said it good-naturedly, but it was clear I should know these things.

The shag is in the blood of people whose parents shagged at the beach forever, shagged here in area clubs for years when they weren't at the beach.

A student named Rebecca Rockholt said, "I've been shagging since I was old enough to walk. My daddy taught me."

Libby and Buck Wallace are taking the lessons. Married 40 years. Libby recalled shagging at "The Pad" more than 40 years ago with her girlfriends after high school as vividly as any part of her life.

"It was glorious," she said. "The shag reminds me of my youth."

Even newcomers to York County know that the shag is not akin to a high school elective. It's a requirement to feel like this really is home.

"I saw the sign for lessons, figured we should learn to shag," said Tim Spyridon, who came from Chicago to York County with his wife, Kim.

But why has the shag endured? Why is it as much a part of so many Carolinians' identities as their families and jobs?

I listened to Whisenant at the class for a long time as he regaled me with history of the shag and its blue-collar roots. The class went on in the background.

This was the second week of a five-week class of shag lessons. Everybody there gave up family time, other things they could do on Wednesday nights, to learn or relearn the shag. All shuffled. The couples held each other's hands or arms in the shag.

Then I saw the eyes of these people. Locked on each other. The smiling faces of every single person in the room. The tender way couples touched each other as the eight-count was repeated again and again and the shuffles shifted on the floor.

And I realized why the shag remains, and hopefully always will.

To shag is to love.