It began as a bicycle race, not so unlikely an event as you might think, as it turns out.

Forty years later Tivoli Day is the end-of-summer celebration of Oak Bluffs. There are no bike races any more, but there is just about everything else.

“Tivoli is like a home grown event,” said Renee Balter, who helped plan many of the events in her past post as president of the Oak Bluffs Association, which sponsors the event. “It just keeps going and going like the Energizer bunny. Everybody looks forward to it.”

In early years, Tivoli Day was primarily a bicycle race. — Alison Shaw

This year’s 40th anniversary celebration on Saturday, Sept. 16, is dedicated to the late Ed Coogan and Michael Wild. Mr. Coogan, a well-known Island attorney, and Mr. Wild, an equally well-known Island conservationist, are credited with founding Tivoli Day.

The name comes from the long gone but not forgotten Tivoli Dance Hall which gained fame in the roaring twenties, and hung on for various other uses until it was demolished in 1964. It sat near the site of today’s police station on the waterfront.

“It was our parents’ and grandparents’ Hot Tin Roof of the day,” said Dennis daRosa, a longtime Circuit avenue businessman and one of the organizers of this year’s Tivoli Day.

The Cottage City Bicycle race drew the best amateur and professional bike racers from around the world to Martha’s Vineyard in the early days. The race was intended to be a link to the past. In the 1880s and 1890s, the smooth roads of Oak Bluffs proved to be quite a draw for organized bicycle races.

“The Vineyard was one of the first places in the country that ever had a bicycle race,” said Bill Stafursky, who along with his wife Margaret, organized the modern-era races. “It lasted for a whole week. The reason they did it was we had macadam roads. It was primarily only in Oak Bluffs. For a number of years there was no Tivoli Day; Tivoli Day was only the bike race. For a couple of years there wasn’t a street fair or anything else.”

In 1978, town officials added a series of events to the fledgling bike race, in hopes of reviving a moribund late season business climate, and Tivoli Day was born.

Bringing Circuit avenue back to life in the shoulder season for more than 40 years. — Peter Simon

A story in the Sept. 15, 1978 Gazette described the event with great anticipation.

“It will be a day of fun and celebration the likes of which Oak Bluffs hasn’t seen in years though much of it — most of it, in fact — was once a normal part of the town’s summer season,” the story said. “Block dances, bicycle races, croquet championships and band concerts are all returning tomorrow from a too long absence.”

Music has always been a big part of Tivoli Day. In the early days of the celebration, Island bands would set up in Healey Square near the Post Office, but the sound reverberated from the buildings so loudly, according to Mr. daRosa, that organizers moved the location to the top of Circuit avenue.

This year Johnny Hoy and the Bluefish headline the event beginning at noon. The Phil daRosa Project takes the stage at 2 p.m., followed by a group of songwriters and rising stars from Nashville, Tenn. at 4 p.m.

In years past musical acts were organized by the well-loved Island blues musician Maynard Silva. Until his death in 2008, all it took was a phone call to get the planning started.

“I do miss Maynard,” said Ms. Balter. “For years, he was the man. You would just call Maynard and say we need bands, we need music for Tivoli Day, and he would put it together. He was quite a character. I miss him.”

In earlier days, the street fair part of Tivoli Day was a little slow to catch on. Some merchants sold wares in front of the stores, but there were gaps because some stores and businesses had already closed for the year. Organizers began to fill in the gaps with artisans and vendors.

“Here it is 40 years later and we have 100 booths, a thousand feet of space sold,” said Mr. daRosa. “It’s just a fantastic boon to the merchants. It’s the biggest fall outdoor festival we have.”

Tivoli Day gets underway at 10 a.m., and continues through 6 p.m. Organizers expect up to 5,000 people to take part in the festivities, which will include outside dining, food vendors, music, face painting, end-of-season retail sales, and raffles.

In the event of rain, Tivoli Day will be postponed to the following day, Sunday, Sept. 17.