UNION — For 127 years, the Union Fair has held fast to the traditions of rural Maine, to the sights, sounds and smells of life on the farm.

A demolition derby notwithstanding, give or take an Elvis impersonator or two, it’s going to stay that way.

“It’s getting harder and harder to stick to the historical, traditional agricultural fair,” said Bud Savage, a tradition himself in his 46th year as fair treasurer. “We work at it. We try to balance that part with new things that keep people coming through the gate.

“We started the demolition derby two years ago, and it’s still controversial — a lot of people don’t think it fits — but it brings in a huge crowd,” he said. “What’s interesting is that a lot who come for that leave saying they liked the oxen pulling or the pig races more.”

The weeklong fair, which runs through Saturday, features a daily schedule of contests to determine the best of Maine livestock from huge draft horses and cattle to poultry and piglets. The nighttime stage is turned over to more contemporary entertainments, such as country singer Dan Seals tonight and Elvis clone James Cawley on Saturday.

For a break from the herds, packs, gaggles and flocks of livestock loitering around the fairgrounds, the Matthews Museum presents an astonishing collection of farm implements and household gadgets of a century ago.

There’s a mint-condition Day’s Self-Heating (and folding) Bathtub from 1900, a cast-iron rendering vat embossed with the faces of smiling cows, a silent movie projector from a time when you could watch a flick at the town hall for a dime, a dog-powered treadmill for old Sparky to help with the butter-churning and enormous old plows that make you really appreciate your desk job.

Nearly lost in the thousands of wondrous things is a great old umbrella with panels bearing advertisements for the W.E. Haskell Co., Union’s leading purveyor of clothing and dry goods. “Insure Your Trousers,” the umbrella cryptically advises.

One entire corner of the museum is devoted to Union’s most illustrious son, Dr. Augustin Thompson, the inventor of Moxie Nerve Food and the source of a controversy that still lingers in a town that takes its history seriously.

“Right around World War II, the town got a bequest from Dr. Thompson’s estate of $40,000 to build a community center and another $40,000 as a fund to maintain it — he didn’t want the building to be a burden on the town,” Savage recalled. “We didn’t do anything with it until after the war and the cost of materials went up so much the town voted to use all the money for construction. So we raise money every year for maintenance. You can still get in a pretty good argument around here about that.”

Fair trustee Janet Boetsch said the organizers work year-round to keep the traditional and the modern in some sort of balance.

“Fairs like this started out as a holiday for farmers to get together after a long hot summer to compare turnips, to see who has the best dairy cow,” Boetsch said.

“With the decline of the family farm, with farmers working harder to make ends meet, we have to always look for new ways to keep the agricultural part going strong. It’s not easy, but it’s rewarding to be part of it. I was going to do this for one year to fill in. Nine years later, I’m still at it. It gets in your blood,” she said.

Ed Barrett, who’s in charge of the cattle events and who knows every cow and exhibitor by name, said the drop-off in big farms has been pretty well offset by the growth of 4-H programs.

“We’re seeing more small animals — sheep, pigs, poultry — than dairy and beef cattle, but now the kids are starting to get into steering oxen,” Barrett said.

“There is kind of a new generation taking up the slack, joining up with us old-timers. We’ve got farmers who’ve been exhibiting here for 50 years, and we’ve got kids 10 and 12 years old who bring in some beautiful animals. There’s no question that the big operations are pushing a lot of small family farms out of business, but if we work at it and keep the kids coming in, there will always be a fair.”