By Mary Campbell

The Associated Press

NEW YORK-Emmylou Harris, DollyParton and Linda Ronstadt can't explain why they sound so good singing together.

"We're glad we do," Parton says. "We do love to sing. Your whole life you wait to find those compatible voices. It's like making love.

"I get off on it. I do. I get so thrilled. When it buzzes, it is good. It's just like sex in that way. Don't fight it."

Their new CD, Trio II, was recently released, debuting in the No. 4 spot on Billboard's country album charts.

The CD was recorded in 1994. But they were too busy to promote it, so the album went on a shelf.

Then Asylum Records contacted Ronstadt at her home in Arizona.

"I still have a contract with them," Ronstadt, 52, explains. "I'm sitting in Tucson where I no longer apply makeup. I'm a servant for two children. They sent someone to my house to ask, 'What do you intend to do with the future of your recording career?'

"I said, 'Well, we have this great record still in the can.'"

To her surprise, Asylum agreed to release Trio II.

When Ronstadt phoned Parton, her response was, "Praise the Lord."

Ronstadt didn't have a copy of the finished record. But all the tracks were located and the CD was assembled without having to rerecord any of the songs.

The pictures on the CD's cover show the three singers when they were little girls.

"Everybody knows what we look like now," Harris says. "It's intriguing to see what people look like as children."

The three singers met in the early 1970s. Several years later, almost by chance, they discovered their voices blended sweetly: Parton visited Harris in Los Angeles, Harris invited Ronstadt over, and they sang a little country harmony. They sang on Parton's TV show in 1976.

Trio, which sold 1.8 million copies, was released in 1987. The album produced four Top 10 hits, including the No. 1 "To Know Him Is to Love Him."

"We are all so very proud of the first Trio record and this one," Parton says. "It's my two favorite things I've ever participated in."

"It's like a gift," says Harris. "I think it's a very special, healing record, the songs and the sound of our voices. I've been listening to it a lot. I'm quite moved by it."

Parton, 53, is hoping the second album will be as popular as the first and would like to record another CD if Trio II does well.

Ronstadt and Harris are less interested in album sales.

"As little or as much as it sells, I think it should be out there for people to have an opportunity to have it," Harris says.

Says Ronstadt, "I'd just like to get a chance to sing together."

Ronstadt is producing a record for Sony Classical on the history of glass music, including a glass instrument built by Benjamin Franklin. She and Harris, who will be 52 on April 2, are working on a record to be released in August.

"I'm trying to write for my next solo record," says Harris, this year's Grammy winner for Same Old Train with Clint Black, Joe Diffie, Merle Haggard, Alison Krauss, Patty Loveless, Earl Scruggs, Ricky Skaggs, Marty Stewart, Pam Tillis, Randy Travis, Travis Tritt and Dwight Yokam.

"I've been trying to take a year off since last January," Harris says. "That hasn't worked out exactly. I have managed to get some writing done. I pretty much let my band go. I left my record company. I wanted to clean out my closet, so to speak, and put all my energy into writing."

Parton has a gospel special on TNN April 1, and her east Tennessee theme park Dollywood will open for the 1999 season in April.