It started with an ad-libbed rap for a class at the Kennedy School of Government (KSG), and grew into a sizeable grassroots campaign summed up with one simple phrase: "Save the Bow."

Stuart Rosenberg, a first-year student at KSG and a long-time patron of the Bow and Arrow Pub, gave the call to arms that resulted an all-day event at the Harvard Square bar yesterday. Several KSG students held a petition drive, hoping to keep the bar in the Square.

Last night, the Bow was packed with customers as early as 7 p.m. and Rosenberg had already collected 300 signatures by 9 p.m., and said he was confident he would reach his goal of 500 signatures by the end of the night.

The bar is housed in a building owned by the Harvard Cooperative Society (Coop), which will soon be renovated--thereby forcing the bar to vacate the premises temporarily.

The Coop administration has said it will raise its rents after the renovations but made no promise to renew the bar's lease. Currently, the Coop is renewing the bar's lease on a monthly basis until the renovations begin.

"I went to Tufts as an undergraduate, and I've been coming to the Bow since 1988," Rosenberg said. "We decided to get a night where people can come, sign a petition and bring their Coop number so [the Coop] can understand that not all Coop members support what they're doing."

Rosenberg initially started the campaign as an assignment for a class he was taking on political action skills at the KSG. But what started out as a for-credit project for the class has grown into a full-fledged campaign.

"We're all Coop members, and we have a share in their decisions. We have a say, or at least we should!" Rosenberg said.

Contract negotiations concerning the new tenants are being controlled by the development corporation, IDM Inc. The Coop said IDM is looking for a single tenant for the space cuurently occupied by the bar and an adjacent Dunkin' Donuts franchise.

This potential set-up is reminiscent of the fate of the Tasty Diner, which occupied a space in the building on JFK St. where the Abercrombie & Fitch clothing store and Pacific Sunwear are now located.

"All the small businesses I've read so much about because of Good Will Hunting are being displaced because of corporate businesses," said KSG student and petition organizer Sean Mao. "The Bow is one of the last places where we can come and have an affordable drink."

Several scenes in Good Will Hunting, a 1998 Academy Award-winning film, were filmed in Harvard Square, including inside the Bow and the neighboring donut shop. The movie was shown at the bar at 4 p.m. as part of the event.

Supporters hope to avoid another scenario like that of the Tasty and they said yesterday they believe that the Bow has a character that is vital to Harvard Square.

"This bar has always been a place of diversity, a melting pot between Harvard and the local working class, with hardly any trouble," said Mike Kelly, who has been going to the bar for the past 25 years. "To let it go would be to effectively kill a small part of Harvard Square."

Charlie Brennan, his friend and fellow bar regular, agreed.

"It's hard to find a place where people get along so well, with the camaraderie between people of such different socio-economic and ethnic backgrounds," Brennan said. "During the day you have all regulars, then at night the college kids come in, and everyone gets along, everyone leaves the Bow happy."

The Coop has told The Crimson repeatedly that negotiations are in the hands of IDM Inc., and that the company will control who occupies the property after renovations. The Coop must, however, approve any final lease of the building, although they will not participate in finding or assigning tenants.

Tiziana Dearing, a member of the Coop's Board of Trustees and a KSG student, says the matter is out of the Coop's hands.

"Whether or not the Bow and Arrow stays is up to the organization that has a contract from the Coop for the property. They are the ones determining how to develop it, what rents to charge and who will have the ability to lease there," she wrote an e-mail message to the KSG students in the Save the Bow group.

She also said the Coop did not have profit-making motives in mind.

"I understand the Bow and Arrow is a tradition, and I admit to being sad it's

going to go. I also understand the Coop's fiscal responsibility to its members, however. Remember, the Coop is not a for-profit company," Dearing wrote.

The focus of the student's petition is to put pressure on the Coop, hoping to strike some sort of a compromise that will allow the Bow to stay in the Square.

"I'm also a lawyer, and I want to see the contract between IDM and the Coop. There has to be some sort of out clause, which gives us a place to start from," Rosenberg said."Who knows what will happen, but at this point there is no negotiations, and hopefully this event will give us a seat at the table."

The bar has been on the same spot, 1 Bow Street, for several decades and even the oldest regulars do not know when it first opened its doors. Several claimed that Bruce Springsteen had his 1969 Boston premier in the bar, performing in the corner where the jukebox now stands.

"I've been coming here for 25 years. This is a place where I've made family," said longtime regular and Allston resident Dave Doyle. "I'm going to keep coming here until they padlock the door. This place has been a major part of my life."