There’s a stir, naturally, as a young audience hears him intone a chapter from his children’s book.

The question was obvious, but it still had to be asked.

Pablo Armendariz showed up outside the Westwood Borders at midnight Sunday to be among the first in a long and winding line of people waiting to order a single children’s book 31 hours later. Two nights sleeping in a lawn chair, two days missed at work, meals grabbed on the fly just to buy a book and get a ticket so he could come back again Thursday to wait in another line to pick up the book, which by then would be autographed.

Why?

Because Paul McCartney had signed it. And on Thursday, McCartney was to hand it to Armendariz, his wife, Rocio, and their 7-year-old daughter, Pariz.

“It’s a once-in-a-lifetime opportunity for my daughter to see genius,” Armendariz said Thursday morning as more than 450 people waited with different levels of patience. “I wish I had had the chance to have a handshake from Mozart, but that’s impossible. But today I’m going to be able to see genius. To me, he’s the best musician who ever existed.”

McCartney’s appearance Thursday meshed classic elements of L.A. -- celebrity culture and the ultra-managed photo op, including ushering journalists out before the event was over. McCartney, who is in the midst of a U.S. concert tour (he plays at the Arrowhead Pond tonight), also recently co-wrote a children’s book, “High in the Clouds,” an environmental tale of animals fighting an evil developer.

As the music tour has worked its way across the country, McCartney has scheduled occasional bookstore appearances like this one, in which he read for an ethnically mixed group of 19 kids, ages 6 to 8, selected by lottery from students at nearby Fairburn Elementary School.

Judging by the crowd outside Borders, you’d think J.K. Rowling was in the house. Except, of course, Rowling would have drawn hundreds of kids. The line waiting to meet McCartney was almost exclusively adults, more gray-haired than not, a crowd that snaked from the front of the store, around the corner and down a block more than an hour before McCartney was scheduled to arrive.

The advance work felt like a presidential campaign. A half-hour before the event, the media -- some 35 cameras and journalists -- were placed in a second-floor reading room beneath a high-domed ceiling and sealed off from the rest of the store by temporary black-curtain walls. Fifteen minutes later, the kids were trooped in to a large blue blanket in front of where McCartney was to sit. One kept holding up sheet music to “Let It Be,” with an orange smiley face on the back, for the cameras.

McCartney didn’t arrive so much as he surfed in on a wave of screams and applause that began outside in the street, moved to the front sidewalk, then the doors before the sound was joined by lighter and more subdued applause from the Borders staff.

Reporters pulled back the black drapes to catch a glimpse as McCartney walked to the far side of the store, then entered the reading room from the side, stopping to hug and greet familiar people.

As McCartney took a few steps to the slightly raised stage, he greeted the youngsters, took off his jacket and settled in a straight-backed chair, the cameras flashing like a thunderless lightning storm.

“Are you Paul McCartney?” one of the kids piped up, his tone sounding as though he was unsure exactly who Paul McCartney was.

“I’m Paul McCartney. Wow,” the former Beatle said, the adults laughing.

McCartney read the first chapter of the book in less than 10 minutes, winged by two plasma screens that showed the pages as he read. Then he asked the kids if they had any questions.

They did. Though in a couple of cases the kids seemed to forget McCartney was in the room with them, starting their questions with, “Why did the author ... “ as McCartney cocked his head, a slight smile creasing his face

There were questions about the characters, the plot, why he picked squirrels and frogs to write about (because “so many of the animals have been done in other stories,” McCartney said) and why, in the opening pages, he decided to kill off the mother of the main character, Wirral the squirrel. And near the end, he was asked why he wrote such a “sad story for children?”

“To make children cry,” McCartney deadpanned.