It is the crescendoing sound of summer, the shouts and giggles of children outmatched only by a chorus of tractors and generators humming and chugging in the distance.

It is the sweet smells of August, of cotton candy, fried dough, greasy hamburgers and sticky sno-cones mixing in the thick afternoon air.

It is the centrifugal force of the Sizzler, the lofty arch of the ferris wheel and the rush of air on the face as bodies move higher and faster toward the sky.

It is the Martha's Vineyard Agricultural Society Livestock Show and Fair, and it is here.

"It's just that exciting time of year," fair manager Eleanor Neubert said on Monday.

Ms. Neubert was busy directing her team of volunteers as they prepared the agricultural hall in West Tisbury for the festivities. Starting Thursday morning, Vineyarders and visitors alike will stream through the turnstiles for four days of fun and food, of livestock and live music, of candied apples and carnival rides.

The 144th annual fair opens at 10 a.m. each of the four days, and closes at 11 p.m. for the first three days and at 7 p.m. on Sunday.

This year's theme is Family Fair Traditions, based on the winning fair poster submitted by Ruth Major. Ms. Major's poster features a cow and her calf with various images of fair agricultural heritage lining the edges.

Yesterday, the grounds were swarmed with workers planning for the big weekend. Outside, carnival manager Darren Cushing laid out the placement of rides and game booths, while West Tisbury volunteer fireman Billy Haynes put the finishing touches on the firemen's hamburger booth. Inside the staff readied the main hall for the hundreds of exhibits that will line the walls and tables. Carpenters constructed temporary walls and building hooks and pegs to hang photographs from shooters of all ages.

Hall manager Kathy Lobb was preparing for her annual 18-hour day on Wednesday, when she will oversee the placement of most of the fair exhibits, a process that goes well into the night.

"There is a reason why things are placed where they are, just don't ask me what it is," she said with a smile. "Where we hang things is basically determined by how well we follow the pictures of the hall from last year's fair."

Entries of all kinds will be judged, from quilts and cookies to canned peaches and fossil collections. Registered exhibitors submitting nonperishables should drop off their entries between noon and 5 p.m. on Wednesday, and those submitting perishables should submit their entries between 7 and 9 a.m. Thursday.

"Whatever happens after that door opens, we're ready," Ms. Lobb said. "There's that excitement on Thursday morning that it's time for the fair. And of course, it's kind of sad on Sunday when we have to take everything down."

Volunteer Lorrie Renker was helping Ms. Lobb set up the hall, but her mind was skipping ahead several days, when she will take place in the women's skillet throwing contest, scheduled for Sunday at 3 p.m. She talked excitedly about the rules and regulations, about the importance of accuracy as much as distance, and the difficulty in achieving both at the same time.

"There's a line and you get two throws to get it as close to the line and as far as possible, or you get points deducted," she said. "You can practice with frying pans if you want, but I throw big bales of hay and shovel manure to get in shape."

In the barn the stalls are empty, but come Thursday afternoon they will be full of livestock of almost every kind. New to the barn and the fair this year will be miniature donkeys.

Numerous events fill a busy schedule. The ox show and pet show highlight Thursday's animal events, and the draft horse pulling contest, always a fan favorite, gets under way Friday afternoon at one o'clock. The 29th woodsmen's contest starts at 1 p.m. on Saturday. The Island draft horse show takes place on Sunday morning at 10 as does the dog show.

There is also plenty of entertainment. Kelly Peters's hip-hop dancers will perform Friday from 2:30 to 4:30 p.m. and again on Sunday from 3 to 5 p.m. The Martha's Vineyard Swing Orchestra performs Thursday evening from 7 to 9 p.m.; the dirty blues of John Barleycorn and the Social Drinkers follow on Friday from 7 to 9 p.m., and Island musicians will share the stage on Saturday night. A brass quintet will also stroll the grounds from 10 a.m. to 2 p.m. on Friday.

Approximately 30 booths will offer everything from fried clams to ice cream, and the old favorites are back. The one and only Mr. Smoothie will be back in his usual place, along with the tempura stand and, of course, the West Tisbury fire department's popular fire engine red hamburger hut.

There are two new additions to the fair lineup this year: Jonathan Wood's raptor project, a collection of large birds of prey, will be on display for the entire weekend, and Toe Jam, entertainment for children, will hold three performances on the main stage on Saturday.

"It's a full weekend, but as usual, there should be something for everyone," Ms. Neubert said.