Graham knows that voice, too. He's such a Julie Andrews fan that, when he was 3, he dressed as Mary Poppins for Halloween, and he went as Maria to the singalong of "The Sound of Music."

Andrews began her day at the District's premier library -- where all patrons must pass through a metal detector, past a large sign warning that guns and knives are prohibited -- in a small room with a glass-fronted door, posing with a few children for the American Library Association's READ posters. A small clot of fans gathered outside, necks craning, jockeying for position.

"Did she look at you?" asked a woman standing nearby. "Did she make some eye contact?"

"Yeah!"

The event was part of what the library association is billing as "the world's largest library convention," which has come to town this week and commandeered, the group says, as many as 25 percent -- 8,452 -- of the District's hotel rooms for the 27,000 people attending.

After the photo shoot -- "she said, 'Thank you for being so good!' " one girl in head-to-toe pink announced proudly as the children filed from the room -- Andrews and her daughter, Emma Walton Hamilton, followed, taking seats in the children's section of the library, where the two read from one of the books they've written together.

Andrews's round, full voice filled the area where P.L. Travers's "Mary Poppins in the Park" and "Mary Poppins Opens the Door" books are shelved, transforming it into an almost Shakespearean-sounding performance space: "Then, of course, I tried to save her!" Andrews read. "I practically threw myself in front of the truck!" The kids followed along in books she had given to each of them.

After Andrews's "little read-through," as she called it, a few other adults spoke and sent the children's attentions immediately elsewhere. One girl balanced Andrews's book on her head. When it crashed to the floor, she began peeling and reattaching two bandages on her arm. Another boy unpinned and re-pinned a book-sloganed button on his shirt.

Then Andrews returned to the podium, where her magnetism was such that Matilda Bode, a 29-year-old documentary filmmaker who'd stopped by the library to pick up a few books on tape, passed by and yelped, "That's Julie Andrews!" She grabbed a friend's arm and dragged him to the back of the room, where she stood, mouth agape, staring.

The woman who once proclaimed "raindrops on roses and whiskers on kittens" to be among her favorite things seemed now to be adding libraries: She will be honorary chairwoman of National Library Week next year.

"Libraries have always been places of opportunity," Andrews said. "Places where everyone . . . can come together."