The backdrop has unfurled in a very L.A.-ish way, as spectacle, as street theater. Past Chinatown's exploding fireworks and dragon dancers. Through a Central American neighborhood festival and thousands of celebrators dancing to a marimba band flown in from Guatemala. Up Vine Street toward Hollywood Boulevard's celebrity footprints--another camera-ready metaphor for more than 500 U.S. and international media representatives who cover the annual Los Angeles Marathon.

The marathon has a signature L.A. feel and look, from its route to its runners, who, over the years, have included Playboy bunnies, priests and nuns, "Spider-Man" and a tuxedo-clad waiter hoisting a champagne bottle on a tray. It is the world's fourth largest marathon, typically attracting more than 21,000 participants from all 50 states and 54 countries, along with a field of elite runners. The marathon also is the largest single civic event in the city of Los Angeles, according to the Los Angeles Convention and Visitors Bureau, and claims a million spectators along the route--matching the crowd estimates for Pasadena's Rose Parade. Organizers bill the event as a 26.2-mile thread through the "multicultural heart of the city"--a reflection, they say, that is as important as the competition itself.

Next time the race is run, March 3, the marathon will undergo a major course revision for only the second time in its 16-year history, weighing race logistics against cultural implications. To assuage runners' complaints and give elite competitors a better shot at record times, two-thirds of the course will shift, mainly via slight reroutes to avoid speed-robbing inclines or turns.

The contours still will include most of the same communities, such as Exposition Park, the Crenshaw District, Cheviot Hills and Koreatown. But the faster, flatter route will omit one of the city's most recognizable areas--the hilly streets of Hollywood, parts of which made up the steepest elevation gain (from 111 feet to 418 feet)--and instead head to the Westside.

"There were a number of decisions that were very difficult for us," said marathon President Bill Burke. "The elimination of Hollywood was particularly gut-wrenching ... the people of Hollywood have just been extraordinary."

Such decisions on how to shape a marathon tend to reverberate beyond the sports world, leading image-conscious organizers to strive for a sense of place and community at their high-profile events. The route of the tradition-steeped Boston Marathon, for instance, has not changed since 1924. And year after year, some 35,000 Red Sox fans turn out at the 24-mile marker near Fenway Park.

In Los Angeles, from its first starting line, the marathon has been defined by the diversity embodied in everything from the ethnic communities included on the course to the race's participants, who include walkers and first-time runners. (By contrast, Boston Marathon participants must meet tough qualifying guidelines.)

"I think probably the greatest thing that symbolizes this marathon is that this is the only recurring event in the city of Los Angeles that turns the city into a neighborhood--people of all races, religions, ages, groups, body types come together and show a brotherhood that is not necessarily experienced the rest of the year," Burke said.

The race has passed through Hancock Park, where residents have set up buffet brunches on wide lawns; through Mid-City and Hollywood, where runners have caught glimpses of the Hollywood sign and snowcapped San Gabriel Mountains; through Silver Lake, where spectators have handed out beers to some athletes, who drink up. Runners say the crowds belie media stereotypes of the city's fractured, self-absorbed populace.

"Gospel choirs in South [Los Angeles], little kids handing out water in Hancock Park, sorority girls at USC, tourists in front of Grauman's Chinese Theatre--all very reflective of L.A.," said USC student Steve Woo, who ran the marathon in March.

The symbolism of big-city marathons, Burke noted, takes on heightened significance during tense times. Organizers of the New York City Marathon did not consider canceling today's event or changing the five-borough course. Near the starting line, more than 30,000 runners will catch a glimpse of the lower Manhattan skyline minus the World Trade Center. This year's marathon will "highlight the diversity, energy and resilience of New York City as never before," organizers said.

After the spring 1992 Los Angeles riots, marathon organizers worried about the message that the event would send: Was the course a sham, a forced link between clearly conflicted communities? Would a surge of runners through the streets trigger fear of looters and chaos?

Politicians and others called for a new route, away from riot-scarred neighborhoods. But Burke and his staff decided against reconfiguring the course around burned storefronts in Koreatown and other neighborhoods. Officials also launched a public relations campaign, saying the city was safe and pointing to the marathon's potential as a metaphor for unity.

In March 1993, hundreds of thousands of spectators--a record crowd--lined the streets to support the 15,000 runners. "What knocked my socks off," Burke recalled, "is that we had over 700 credentialed press. They all came here to see this thing explode. They all [expected] beatings and blood in the street, and once again, this event was a love fest. I remember clearly [Ted Koppel] on 'Nightline' interviewing us to ask, 'How did this happen?"'

Burke, who is married to L.A. County Supervisor Yvonne Brathwaite Burke, co-founded the city's marathon in the afterglow of the city's feel-good 1984 Olympics. A businessman who served as the Games' commissioner of tennis, he understood the cinematic and moral power of symbolism from race day No. 1. The first marathons started at the Coliseum, the site of two Olympic Games, and took runners through an eclectic cross-section of the city including skid row, Olvera Street, Silver Lake and Chinatown. (Runners no longer pass those areas, which have been struck from the route over the years in ongoing refinements.) The first major course change, in 1996, moved the starting line downtown in an attempt to forge a faster route and showcase businesses there.

In the past three years, pressure has mounted for another course change, with requests coming from casual athletes and the elite runners who would raise the marathon's profile. This year, marathon Vice President Nick Curl designed a flatter course, taking in recommendations from city officials, civic leaders and more than 30,000 marathon veterans.

Under the new plan, the race will kick off at Grand Avenue and 3rd Street, near the rising stars of the skyline--Frank Gehry's Walt Disney Concert Hall and Jose Rafael Moneo's Cathedral of Our Lady of the Angels. Runners will head farther west than ever before, to Robertson Boulevard. (The previous westernmost point was Fairfax Avenue.)

The pack will pass City Hall for the first time since 1995, make an inaugural run through the 2nd Street tunnel and shoot past a panorama of L.A. images from broad streets lined with palm trees and Tudor-style mansions to colorless blocks crammed with mini-malls and gas stations.

The City Council approved the rerouting in September, with Councilman Eric Garcetti casting one of two dissenting votes. Garcetti objected to the bypass of Hollywood, which is in his district, and said he would fight to include the area in next year's course. A world-class marathon should include Hollywood, he said, "a symbol of not just the city but our country. Most people [around the world] get their impression of the United States through Hollywood." Besides, said Garcetti, a marathon runner himself, Hollywood isn't that hilly.

On every marathon morning, the Hollywood Arts Council has thrown a party on Hollywood Boulevard. Partyers have dressed up as Frankenstein or Lucille Ball or Groucho Marx and danced to an oldies band. Some runners wiggled their hips or pumped their fists to the music, or sang along to Garth Brooks tunes. "For one Sunday a year, we really become one city, one event that links us all," said Nyla Arslanian, president of the arts council.

Arslanian said she is disappointed that such an important part of the city is being left out. She added that the arts council, which has "enjoyed a wonderful relationship with the marathon," hasn't decided whether to claim a spot on the new route. (Dancers, bands and other sanctioned groups displaced by the realignment will be offered new locations.) "I would have to say our hearts are in Hollywood," she said.

Just outside Koreatown, a tweak in the course's contours means that runners will no longer pass the grand neo-Romanesque Wilshire Christian Church on South Normandie Avenue west of Wilshire Boulevard. The church's scrapbook includes pictures of race day, when a gospel choir sang from the balcony and bagpipers serenaded the runners. Young people organized a Saturday night sleepover at the church so they could get up early Sunday morning and greet the runners. In front of the 74-year-old church, the Rev. Donald Colhour, along with the pastors from the Latino and Korean congregations, blessed the pack. Some runners dashed into the sanctuary for a prayer and then rejoined the field.

Colhour isn't sure whether the church will participate in the 2002 marathon. "We have this huge, historic edifice and balcony," he said. "It was the perfect setup for us to do all of this. To be quite honest, I'm a little disappointed." (Marathon organizers recently began notifying the 80 participating community groups about the route changes but have not yet signed up new organizations along the 2002 course).

In the little village of Hayfield, England, 43-year-old runner Liam Mycroft has followed the debate over the marathon's rejiggering. He is a serious runner, focused on setting personal records in each race.

In March 2000, Mycroft ran the L.A. course in the pouring rain, posting a respectable time of 3 hour 33 minutes 59 seconds. (The men's division winner, Kenya's Benson Mbithi, 22, finished in 2:11.55).

But Mycroft still noticed the Laurel and Hardy look-alikes in Hollywood, the gospel choir in the mid-Wilshire District, the bedraggled but hearty spectators, all of whom transformed his image of Los Angeles.

"Some of my friends said, 'There are parts of L.A. you don't go to, dangerous places,' and perhaps some of the marathon goes through the rougher parts of L.A. But I didn't feel threatened in any way, shape or form. My impression was, 'This is a together place.'" Mycroft, who works as a union official, said he would run the marathon again on either the old or new course.

"How flat the marathon is strikes me as really irrelevant. Personally, I look for an interesting place to go."