“Float” couldn’t be better named. The free series of artworks and live performances, which continues this Saturday and Sunday at Socrates Sculpture Park in Long Island City, is as ephemeral as the clouds that drift over this waterfront oasis of art. But ephemeral doesn’t mean these amusing and often beautiful pieces won’t leave lasting impressions.

“In the past two ‘Float’ exhibitions, we emphasized the site,” the curator of the series, Sara Reisman, said. “This time I chose to focus on a theme — nostalgia for a future past — that seems to resonate with a wide range of artists. This nostalgia is for a time in our youth when we believed in a fantasy of the future, a kind of science fiction utopia. This vision of the future receding into the past expresses the ephemeral and time-based qualities of the works in the exhibition.”

To explore the theme, Ms. Reisman invited a far wider range of media to participate in the popular series than she has in the past. There will be a concert by the hot, New York indie rock band the Fiery Furnaces on Sunday, along with a newsprint publication and a Web log. Near the entrance to the park will be a continuously looping series of films by Robert Boyd, William Lamson, Shana Moulton, and Ola Vasiljeva, focusing on ideology, identity, and spiritual transformation. These range widely from Mr. Boyd’s videos of cult rituals and Ms. Moulton’s of a desperate woman searching for meaning through self-help videos to Ms. Vasjiljeva’s animations of characters such as Michael Jackson singing opera, and Mr. Lamson’s film about the properties of weightlessness.

For his installation piece “Missing,” the Dutch artist Jan Rothuizen, who is also a magazine illustrator and writer, collected messages that were placed on trees and walls by people who were seeking help in finding their missing animal, human, and inanimate loved ones. In one, a sheet of paper shows the picture of a girl along with her details, such as the color of her hair, her height, her name, and the clothes she was wearing on the day she disappeared. By associating these facts with details from other stories, both fiction and nonfiction, viewers can construct a dramatic image, and figure out how the girl got lost in the woods and disappeared into the night.

Performance artist Saya Woolfalk also explores loss and longing. Partly influenced by her being the daughter of a Japanese mother and mixed African-American and white father, she examines how the past affects the future and how our fantasies of the future shape our present. Ms. Woolfalk built her fantasy structure “No Place” for the future employing waste materials of the past.

“It’s recycled material from my home,” she said. “I like to use common, everyday material in my work. I think it makes it easier for people to feel a closer to my work. The building is supposed to be a gateway to utopia, where relations are good between classes and races, but of course it disintegrated over the three weeks in the park. That’s its melancholic aspect.”

Not so melancholic will be the performance by Ms. Woolfalk’s collaborator Shaun Leonardo, who on Saturday will conjure up images of warriors and superheroes to inform a dance related to the piece. “I like collaborating with performers,” Ms. Leonardo said. “Their approaches can change everything.” A painter and sculptor as well, Ms. Leonardo has a show coming up at the Heidi Cho Gallery in September.

Lishan Chang’s installation “LC Space@SSP”involves no performers, though sun, wind and light will surely affect his stunning, luminescent sculpture, which he created by stretching plastic wrap around trees and wooden poles. Like master wrapper Christo, Mr. Chang contrasts the man-made with the natural, though in his hands the unnatural plastic wrap becomes as silvery and beautiful as the leaves on the trees and the water lapping at the park’s edge.

“I made plastic wraps intercrossing among telephone poles and trees,” Mr. Chang said, “so that there were small spaces between the plastic panels that people could walk through in order to experience the different space, light, and changing scene. As spectators come walk within the art installation, they can look through the plastic wraps and see a completely different world. On the other hand, they also become part of the installation to be looked at by other onlookers. We are part of art and art is always with us.”

In fact, not everything at “Float” will disappear after the weekend’s festivities. Visitors can take home a series of stickers decorated with a new symbolic code and Jeanette Doyle’s newsprint publication, “When Art (or In What Regard),” in which 15 curators, artists and critics respond to questions asked by Ms. Doyle and Ms. Reisman on the status of art.

No doubt, many works in “Float” will be long remembered.

Until August 26 (Broadway at Vernon Park Boulevard, Long Island City, Queens, 718-956-1819).