MANCHESTER, Tenn. - The eighth annual Bonnaroo Music Festival got under way Thursday with stormy weather, but it did little to dampen enthusiasm as music's favorite beach bum unexpectedly joined the lineup.

One act, the San Diego rock band Delta Spirit, had their set postponed several hours because of weather-related travel difficulties. But the festival announced a late addition so identified with sunny weather that he would seem a hopeful good luck charm: Jimmy Buffett.

Buffett, who started his career in Nashville before finding his musical path in the Florida Keys, was scheduled to play Saturday, joining Ilo and the Coral Reefer All-Stars, a group led by a friend of Buffett's: guitarist Ilo Ferreira.

The Thursday evening slate of Bonnaroo was a mere appetizer for the 3-day megafestival, held on a 700-acre country site about an hour's drive south of Nashville. A handful of buzzed-about bands - White Rabbits and Passion Pit among them - took to one of the festival's five stages and enjoyed a dry early evening before lightning and rain returned.

More than 100 acts were to follow in the coming days, including headliners Phish and Bruce Springsteen.

This year's Bonnaroo bowed with hopes for a greener festival, aiming to cut down on two scourges typical of giant festivals: trash and water bottles.

One of the more curious sights at this year's festival is the many volunteers stationed around the grounds next to garbage cans. The volunteers - dubbed "trash talkers" - have been positioned to make sure people dispose of trash correctly in bins for either recycling, compost or "landfill."

The festival got an especially large amount of volunteers this year (many of those working on the festival grounds work two shifts in exchange for free tickets to Bonnaroo), and so approximately 400-450 of the excess volunteers were made trash talkers. The effort is being led by Clean Vibes, a company that seeks to minimize the environmental impact of festivals.

Chris Morales, a 25-year-old from California, delighted in the task.

"I love it," he said. "I'm in the middle of everything and people seem to really appreciate it."

Morales didn't hesitant to pull out items that had been tossed in the wrong can.

"I can always wash my hands later," he said with a grin. "The world can't wash its hands."

Another effort this year is to get people drinking water not out of plastic bottles. The festival partnered with thermos and bottle-maker Stanley, which is selling bottles that can be filled up at free water stations.

Stanley was keeping a tally of the water bottles saved at Bonnaroo, factoring a gallon of water a day per each bottle sale - $1 of which goes to the clean water organization Global Water Challenge.

Their number was approaching 70,000 early Thursday. JoAnne Anderson, consumer marketing manager for Stanley, said they hoped to reach 2 million by the end of the weekend.