combined with a projecting grille, side vents, and rear fender “hips,” and it looked like nothing else on the road. With long hood and short rear-deck proportions and lines that were crisp, clean, and modern, the car was like a pop song with a catchy hook.

It also seemed in keeping with the fashion of the day, the tall-boot and miniskirt look. Indeed, the Mustang seemed just the car for the growing number of single workingwomen. But, like a good pop song, it could be played in many ways, “covered” in different styles.

It was planned, produced, and introduced in the shadow of Ford’s Edsel debacle of 1958, and every bit of bad luck that seemed to have afflicted the former was reversed with the latter. Its introduction was a masterly piece of publicity and marketing. Carefully leaked spy shots whetted the public’s appetite. Ford’s PR men retailed anecdotes too good to bother verifying: the man so riveted by the new Mustang that he drove his pickup truck through a show window; the buyer so enamored of his new car that he slept in its front seat locked in the dealership overnight while his down-payment check cleared. Lee Iacocca appeared on the covers of Time and Newsweek. The car even received a design award before it was introduced, from Walter Hoving of Tiffany.

And the World’s Fair offered a perfect stage. The ambitious industrial pageant might be recorded as one last moment of naive optimism about progress and the unalloyed promise of the future. Ford’s pavilion, whose “Magic Skyway” carried visitors from the days of the dinosaur to a future of bubble-like buildings, was designed by Disney. Tomorrow was open to all. Dr. Martin Luther King, Jr., was photographed riding through with one of his children.

The Mustang broke old patterns, among them the industry’s tradition of September introductions. It was called the “19641/2 model.”

In his book The New Industrial State, John Kenneth Galbraith argued that the development and introduction of the Mustang was as representative a process of its era, as the famous pin factory Adam Smith had written about in 1776. It suggested the dynamics of an economy in which manufacturing was dominated by bureaucracies responsible for sales, marketing, and advertising.

Soon, the buyer was offered a V-8 engine. Lee Iacocca went to the race engineer Carroll Shelby in the fall of 1964 to have him make the Mustang into a genuine racecar. GT, Boss, Cobra, and other models followed in the succeeding years.

When GM responded to the high-power Mustang with the Chevrolet Camaro and Pontiac Firebird, and Chrysler with the Barracuda and Marlin, a new name for the type of car was born: “pony car.” Mustangs, with more powerful engines, opened the way to another new category of vehicle: the “muscle car.”

The high-power models widened the appeal and changed the image of the car. At first, the Mustang was associated with independent young single women who were slightly intimidating to men, an image cemented by the hit soul song of

1966, “Mustang Sally” by Wilson Pickett.

But Steve McQueen also gave the car tough-guy associations in Bullitt (1967). It could play as a character on its own, as proven by its supporting role in the 2000 film Gone in Sixty Seconds. “Eleanor” is an elusive, temperamental 1967 Shelby GT500 that plays opposite Nicholas Cage.

There were many successive styles. Even the ugliest Mustang could have iconic power, as shown by Vanilla Ice, whose homely 5.0 Mustang starred with him in the 1990 hit video of “Ice, Ice Baby.”

Like the Porsche 911, also introduced in 1964, the Mustang allowed for evolution. The design remained remarkably consistent through the years; lots of different cars could look like a Mustang. Despite Ford’s seeming efforts to wreck the franchise, it has hung on. It came to the edge of cancellation in 1989; a new model in 1994 saved it.

J. Mays, the head of Ford design known for this “retro-futurist” approach to channeling great models of the past, found perfect material in the Mustang when it came time to redo it for 2004. His take, based on the 1967 version of the car, with elements of the 1966 and other models, has been a success in sales and reviews. The Mustang, Mays passionately declared, “is a legend, an icon. It has long since ceased to be an automobile; it is a sense of national pride.”