"The first time I heard 'You've Got a Friend,' " says Melissa Manchester, "I thought that should be the national anthem."

Manchester, who will be appearing Thursday at the Merriweather Post Pavilion, sticks to the emotional basics with a repertoire that includes "Come In From the Rain," "Don't Cry Out Loud," "Midnight Blue" and "Whenever I Call You Friend," which she wrote with Kenny Loggins.

"I am a completely emotional person," she said in a recent phone interview. "Sometimes I feel like the left side of my brain has never developed at all. There's a lot of oatmeal dripping out of my ear."

Manchester's emotions have taken her a long way. She broke into the New York show business scene in her late teens as a street performer, coffeehouse singer and staff writer for a New York music publisher. Later she was a backup singer for Bette Midler and Barry Manilow. Her appeal today is much the same as it was then.

Sure, she traded in blue jeans, frizzy locks and a few pounds for tight gowns and a punky hair swirl, but she is true to her art: "I write out of the joy of writing and that's what I do. Some people sketch, and I write. And I feel very fortunate that I can make a living doing this."

She also does a lot of work for humanitarian causes such as Pro-Peace, which recently adopted her song "We the Living." She performed the tune at a rally attended by 10,000 people.

Manchester has also been a proponent for women's rights, having contributed to the PBS documentary "Woman Alive" with Gloria Steinem. One of her albums was titled "For the Working Girl." It didn't sell nearly as well as her Grammy award-winning single, "You Should Hear How She Talks About You."

Manchester said she was surprised to win, but quipped, "As you accept the award, you notice it starts collecting dust."

Her musical success is grounded in a childhood spent with creative parents in New York's Upper West Side. She grew up writing poetry and participating in spirited dinner table discussions with her father, a bassoonist for the Metropolitan Opera Orchestra, and her mother, a sportswear designer.

She entered the High School of the Performing Arts, where she studied acting and auditioned for roles on the side. She also took a New York University songwriting course with Paul Simon, whom she cites along with Joni Mitchell, James Taylor, Laura Nyro and the Beatles as a major influence.

Manchester admires Rodgers and Hammerstein as well as Lennon and McCartney, and she borrows a little of both in her songs. Like Loggins, she keeps up with the production trends. On her latest album, "Mathematics," she worked with four producers to create a diverse sound.

"With four producers, they're really on their toes. And there's a healthy kind of competitiveness." There is a drawback, however: "You have to put your more esthetic closet side in the back burner."

Manchester said she doesn't know what the future holds for her, but she looks forward to it. "There are a lot of things I'd like to do. Most of them I'm not aware of. But I'm sure they're out there."