VINALHAVEN — On a glorious mid-September afternoon, Robert Indiana walked into the sun-splashed backyard of a friend’s home and blushed.

A few dozen of his most trusted advisers and colleagues secretly gathered to celebrate the artist’s 80th birthday, and began singing the Beatles song ”All You Need Is Love,” invoking Indiana’s iconic ”LOVE” sculpture.

”Let the party resume,” Indiana said as the song petered out, clearly embarrassed, but touched, with the attention.

Someone asked if he wanted to address the occasion of such an important personal milestone.

”No,” he scoffed, smiling. ”It’s something I’d rather forget.”

But there’s no escaping Indiana’s past, or contemplating his future. Having spent the past 30 years deeply ensconced on Vinalhaven island off the Maine coast, Indiana enters the ninth decade of his life boldly making new work. He just opened a sculpture show at Paul Kasmin Gallery in New York, and his France-based art dealer continues to place his work in the major cities of the world – Paris, Madrid, Lisbon.

A new sculpture, called ”HOPE” – modeled after his design of ”LOVE,” with the letters stacked two in a row with a crooked ”O” – was front-and-center at the Democratic National Convention in August, once again renewing Indiana’s interest in politics that began with the presidency of John F. Kennedy.

His motive in designing the piece was simply to remind people that better times may be ahead. ”It’s getting worse and worse. We need hope more and more,” he said.

Indiana also is working closely with the curatorial staff at the Farnsworth Art Museum in Rockland in preparation of a major show next summer. The Rockland exhibition will focus on the work that Indiana has produced since moving to Maine in 1978, although the museum is seeking permission from the city to electrify and place Indiana’s famous ”EAT” sign on top of the museum, to beam out across Rockland. The sign was part of the World’s Fair in Queens, N.Y., in 1964-’65.

Age, he said, is mostly irrelevant. ”I would really prefer not thinking about it,” Indiana said during an interview after his surprise birthday party. ”Most people insist I do not look my age. I would like to keep it that way if I can.”

More important than age is attitude, he said, and ”HOPE” embodies Indiana’s mindset these days.

He’s lived with the word since moving into the Star of Hope, the old Odd Fellows Hall on Vinalhaven that has been his home and studio for 25 years. The word appears on his stationery, and he’s been using the motif in his work for some time.

But the ”HOPE” sculpture, fabricated this summer at the Eliot-based Green Foundry of Josh Dow and Lauren Holmgren, is entirely new. The success of the sculpture and its commercial applications – prints, pins, posters – may be tied nearly directly to the success of the campaign for president of Barack Obama, but Indiana’s handlers believe the 6-foot stainless steel piece has the potential to define both a generation of young people and the direction of the country.

Just as ”LOVE” helped define a time and place during war in the 1960s, ”HOPE” can do the same today, said Michael McKenzie, who runs American Image Atelier in New York, which is handling the ”HOPE” campaign.

”Every generation is getting a tag, and not all those tags are entirely complimentary,” McKenzie said. ”You have the Me Generation, the Slacker Generation, Generation X. But when you call a generation the Hope Generation, it’s a completely different story. You’re asking the generation, ‘Look, we didn’t do it the right way. Take the ball and do it right.’ That’s where we are in America right now, and Bob is in a perfect position to show the way.

”In the case of when Bob did ‘LOVE,’ the Love Generation was formed by the time Bob got to it. In this case, the Hope Generation is forming around his piece.”

McKenzie believes that ”HOPE” could become what ”LOVE” became – iconic, and nearly universally recognized. ”LOVE” began as a Christmas card in 1964, and ended up as a postage stamp a decade later.

Indiana is skeptical.

”Michael has reached the conclusion, and I do not entirely agree with him, that ‘HOPE’ one day will be on the same level as ‘LOVE.’ That would be nice, but I think he is being very optimistic,” Indiana said.

At the party on Vinalhaven, Dow and Holmgren met Indiana for the first time. They had spoken with him on the phone previously, but never met him face to face until the party.

Both are young artists, just out of art school. Dow called the experience ”absolutely profound,” and Holmgren termed it ”surreal.”

”We were art school students,” Dow said, ”and we learned about Robert in art history class. This project is at the nexus of social, political and artistic applications. Hope is such a wonderful word right now.”

For his part, Indiana said it was important that ”HOPE” be made in Maine, if at all possible. All the better that it could be fabricated by a pair of young artists, just starting out on their own. ”I like that very much,” Indiana said.

Born Robert Clark in New Castle, Ind., in 1928, Indiana came east in the 1950s and joined up with the Pop art crowd. Since his very early days, he has always treated his paintings, sculptures and prints as visual poetry. He fills his images with words, letters and numbers, and is particular about symmetry and geometric balance.

His work is in the collections of major museums around the globe, and he’s long maintained a visible presence in Maine. He first came to Maine in 1969, and moved here permanently in 1978, settling in Vinalhaven.

It hasn’t always been easy, on many levels. Moving to Maine meant less exposure for his work in New York and other major art cities, and some local people were slow to embrace his presence on the island, if at all.

”I always got the message very early on that summer people were not anybody’s favorite people, so I would come only in the fall, which is September and October, the two nicest months here anyway. And when I moved here permanently in ’78, the islanders had their game of territorial sovereignty. For a while, it was kind of rough – broken windows and such. But I understood it was a ritual.”

Indiana withstood the hassles, and now has spent 30 of his 80 years living year-round in Maine.

Indiana’s dealer, Simon Salama-Caro, has no doubt that Indiana lowered his profile by moving to Maine. But for him, the sacrifice was worth the trade-off, his dealer said. ”He wanted to be left alone,” said Salama-Caro, who flew in from France for the party. ”But he has continued making great work, and that is what we are promoting.”

Indiana recently traveled to New York to attend the opening at Paul Kasmin Gallery.

He had a wonderful time, enjoying the company of friends and taking in a preview performance of ”Equus,” starring Daniel Radcliffe. He also appreciated the vast array of food that Manhattan offered.

But New York proved exhausting. ”Too frenetic. Too many people. Too many new skyscrapers. Too many automobiles. Too much of everything. It is refreshing to be back in the quietude of a peaceful island off the coast of Maine,” he said.

Donna McNeil, chairwoman of the Maine Arts Commission, said it reflects well on Maine when someone of Indiana’s stature receives such prominence, as the artist did with his sculpture at the political convention in Denver.

”There we were, front and center. If you’re really original, you’re going to lead the pack, and that is what Bob has always done,” she said.

”I was very pleased that a Maine artist was prominently featured at a national event, and it couldn’t be more perfect to have someone who was so emblematic in the ’60s to be present in this time of change.”

Lora Urbanelli, director of the Farnsworth, said the museum is planning next summer’s show as a ”major splash.” In addition to putting the ”EAT” sign up on the roof, the museum hopes to place sculpture outdoors in the sculpture garden and paintings, prints and other work indoors in the galleries.

”We’re going to focus on Bob’s time on Vinalhaven. We’re excited about Bob and his last 30 years, what he’s been doing out here, and not just the work he has produced, but what that self-imposed isolation has meant to him and his creativity. We’re going to talk about the Star of Hope and how that building has influenced him. Bob is a major member of our community, and it is very important that he be recognized as such,” she said.

Time will determine Indiana’s place in the art history books. He’s already in most of them, because of ”LOVE.”

Salama-Caro is certain he will remain there, no matter the outcome of ”HOPE.”

”His legacy is enormous. He is truly a giant American artist.”