An excited, yet not quite frantic, bustle around West Tisbury's Agricultural Hall suggests that it's that time again. Just in case the hectic scene isn't enough of a sign, a yellow, blue, green and pink merry-go-round sits empty in the grass semicircle in front of the Agricultural Hall, waiting to take kids for a spin.

The 140th Martha's Vineyard Agricultural Society's Livestock and Fair will kick off Thursday morning at 10 a.m.

The theme of this year's fair is Agriculture in Bloom. The fair offers the timeless demonstrations and competitions that make the event a long-awaited summer occasion - but fair manager Eleanor Neubert promises a few new twists.

For starters, the planning committee has invited some off-Island musical talents for nightly jam sessions. Jenny Paquette, popular in the New England fair circuit, will take the stage Thursday night at 7:30 to perform a broad country music repertoire. Spectators will still enjoy a taste from the local music scene, as Ernie Thomas delivers an open stage call to all fiddlers on Friday night. Saturday night, a steel pan (drum) band, Mentos and the New Horizon, will offer a blend of calypso, soca and reggae music at 7:30 p.m. Kelly Peters will deliver a history of hip hop Sunday evening, and his students will strut their skills. The stage will be situated near the center of the local booth area this year.

If it's the carnival rides luring you and the kids to the fair, Ms. Neubert boasts that a total of 18 rides will be scattered throughout the grounds, a record number. The fair will offer riders an inaugural ride on a brand new ferris wheel.

Also new to the agricultural fair this year is a tent for spinners and weavers, where artisans will demonstrate their craft throughout the day. The animal whose coat provides the weaving material will be found grazing about their feet.

While the fair committee prides itself on maintaining rituals created long before they took the reigns, the committee took a plunge into the 21st century this year, beginning the initial phases of computerizing the entry and judging sheets.

There is other change as well. Volunteer Jane Newhall, whose service at the agricultural fair dates back to the late 1940s, couldn't make the summer trip east this year.

"The whole fair committee has been missing her," Ms. Neubert said, recalling how Ms. Newhall took the late night merry-go-round ride with other volunteers just last year.

While the agricultural fair expands and adapts each year to accommodate the changing interests of the community, it's the timeless elements that keep the crowds coming back year after year.

"They'll be guaranteed to see the merry-go-round and ferris wheel in the half circle, and they'll find some fried dough somewhere in there," Ms. Neubert said.

Her list continues: "The firemen's hamburgers, the local school kids' ice cream, Bill Smith's lobster rolls, Leslie Gray's Southeast Asian clothing," she said, peering out the back windows of the Agricultural Hall, trying to visualize the repeat vendors.

Categories for entries demonstrate much staying power as well.

"Some of them are the same as they've been for a hundred years," Ms. Neubert said, naming flower, jelly and vegetable categories.

The friendly competition among contestants is as familiar as the categories themselves.

"Not only do you have neighbor against neighbor, you sometimes have husband against wife," said Kathy Lobb, hall manager for the fair.

"There's no swapping of secrets, either. They don't give it away," she added.

From needlework to brownies, Vineyarders can put their skills to the test against friends and neighbors in dozens of categories. The deadline for entering was last night. Participants can bring their submissions to the hall between noon and 5 p.m. on Wednesday. Contestants cannot sneak a peak at the blue-ribbon winners until early afternoon on Thursday, when the hall opens after the judging.

The ever-popular dog show will begin at 10:30 a.m. on Saturday. Four rings will run simultaneously to cut down on the wait for dogs and owners alike.

Don't miss the clam and oyster shucking contest, which is now joined by the smoked fish contest. This salty showdown will begin at 4 p.m. on Friday.

The 25th annual woodsmen's contest will give participants a chance to take a swing at top prize. Wood chopping will be rivaled by a women's skillet throw early Sunday afternoon.

All this and more can be experienced Thursday through Sunday at the Agricultural Society barn on the Panhandle Road in West Tisbury. Fairgrounds open on Thursday, Friday and Saturday at 10 a.m. and close at 11 p.m. On Sunday the fairgrounds open at 11 a.m. and close at 8 p.m.

Adult tickets for each day are $7, $5 for seniors, $4 for children. Parking is available in fields around the hall.

Fair-goers who take the Vineyard Transit Authority shuttle bus to the fair can receive a stamp for a $1 discount at the door. Shuttle buses will leave the Steamship Authority wharf in Vineyard Haven every half hour starting at 9 a.m. and running until 11 p.m. From Menemsha shuttle busses will run to the fair every hour, departing at 20 minutes after the hour starting at 9:20 a.m. From Aquinnah and Chilmark, fair-goers can transfer in West Tisbury. Busses will leave on the hour from Church Street in Edgartown beginning at 9 a.m. and will run every half-hour from 12:30 p.m. through 10:30 p.m.

Ms. Neubert said for many Island people, the fair is a summer reunion of sorts. "The fair brings people from far and wide - people who've been a part of it since they were children and those just coming in for the week," she said.