NASHVILLE, Tenn. — Know the children's book "Boom Chicka Rock"? Lynne Beery does — almost word for word.

The day it arrived in the mail as part of the Imagination Library program, her 4-year-old daughter, Heavenly, asked her mom to read it 25 times. That's more than 25 refrains of "Boom chicka rock, chicka rock, chicka boom!"

But Beery is not complaining. She likes having that time with her daughter, who has Down syndrome. Each month, when a new book arrives, the little girl has the same reaction: "She'll open the mailbox, grab it and jump on the couch with the book. I have to stop whatever I'm doing and read right then."

The excitement is a big reason for the growing popularity of Imagination Library, a children's literacy program started 10 years ago by country singer Dolly Parton in her native east Tennessee.

The program now is in 572 communities in 41 states, including Hawai'i (see accompanying story). This year Tennessee became the first to take it statewide; some lawmakers in Indiana want to do the same.

Sharyl Emberton of the National Center for Family Literacy in Louisville, Ky., said Imagination Library is well-structured, relatively inexpensive and — judging by what she hears from parents and educators — effective.

"We've worked with other literacy programs that put books in families' hands, but in my opinion this one is the best," she said.

"There's really a lot of attention paid to the kind of books they send to children, and the books are mailed directly to the child. ...

"We're talking about families that don't have access to books. And it's a continuing thing. A lot of the other programs don't have that kind of continuity."

Children who sign up are mailed one free book a month from birth to age 5, regardless of family income.

The books are chosen by a committee of specialists and are age-appropriate, with bright colors and shapes for infants, letters and numbers for toddlers and more complex story lines for older children.

The series begins with "The Little Engine That Could" and ends with "Look Out Kindergarten, Here I Come."

In Tennessee, the cost is $27 per child, with half the money coming from the state through matching grants and the rest from the communities, whether local governments, businesses or civic clubs.

So far, 90 of Tennessee's 95 counties are on board.

"It's just one of those things that when I heard about it I thought, 'What a great idea. Why didn't I think of that?' "' said Tennessee Gov. Phil Bredesen, who made the library part of his campaign platform and then secured $2 million for it.

Funding varies by location. For Emberton, director of the literacy center's program for American Indian families in 16 states, the cost of providing Imagination Library to about 2,500 children is paid by the U.S. Bureau of Indian Affairs.

The program was born of Parton's experience growing up in the Smoky Mountains, where children's books and education were luxuries.

She often wonders what her father, a tobacco farmer who scratched out a living for 12 children, could have accomplished had he known how to read and write.

"He couldn't write his own name. He wouldn't even recognize our names if he saw it on a paper, but my dad was one of the smartest people I knew. He just didn't have an opportunity to get an education," Parton said.

"I've had a scholarship fund for years, but I started thinking wouldn't it be great to start the children when they're little, when they're most impressionable, to teach them how to read, teach them how to learn to love books, just to have them, to claim them."

State officials say that 35 percent of kindergartners arrive at school unprepared, with many never having been read to or even having books in their home. Once they start behind the curve, it's hard for them to catch up.

A 2004 study of Imagination Library by the Tennessee Board of Regents said reading aloud to children helps them acquire the skills necessary to read, contributes to parent-child bonding and leads to higher reading achievement in school.

The study found that in one county, Macon, libraries noticed an increase in children applying for their first library cards, with most being recent graduates of Imagination Library.