IN a soaring glass case in Paris's most prestigious haute-couture museum -- formerly the venue for retrospectives of filmy Givenchy and Pierre Balmain confections -- stands a pair of Levi Strauss & Co.'s 501-XX, five-pocket jeans, backlit by tiny lights.
''At first, we had serious doubts about this project,'' says Catherine Join-Dieterle, curator of the Musee de la Mode et du Costume at the Palais Galliera. ''Unlike most of our retrospectives, the subject of this exhibit isn't gorgeous. Nothing looks more like a pair of jeans than another pair of jeans. We were afraid people would be bored.''
''But Paris's haute couture is in deep crisis,'' she adds. ''There's a point in asking some new questions.''
Denim's fashion lesson
The question is simple: Jeans have found a worldwide audience; they are worn on all continents, by all classes, all ages, and both sexes. Haute couture has a very narrow clientele that's getting narrower. Can a world of sumptuous silks and sequins learn something from blue denim?
Christian Dior's waist-cinching ''New Look'' gave the French high-fashion industry a new audience in 1947. After years of wartime austerity and cloth rationing, Dior's long full skirts and sleek lines attracted customers and imitators. A generation later, the industry faced competition from designers' lower-priced, ''ready to wear'' collections and jeans. It also confronted a new set of expectations about how women live and work.
''The average cocktail dress you'll see on a Paris runway costs $20,000,'' Ms. Join-Dieterle says. ''Once, women were viewed as a reflection of their husbands; a woman's clothes were an expression of her husband's status. Now, more women are working themselves, and such clothes are inappropriate. Women travel more; they buy other things. And times are more dangerous. Even luxury cars in Europe are advertised as costing much but not showing it.''
''Paris haute couture won't die,'' she adds. ''But it will have to change.''
The exhibit uses garments, manufacturers' notebooks, old photographs, and advertising pieces to build an argument about how jeans conquered a world market. ''We worked as archeologists, trying to rediscover threads of history,'' she says.
The southern French city of Nimes is credited in many textbooks with discovering the blue fabric (Serge de Nimes) that became known as denim, which some claim was then exported to Levi Strauss in the United States. When American jeans conquered France in the 1950s, according to many accounts, it was only a return home.
''This version is a historical mistake,'' insists Join-Dieterle. Serge de Nimes was about the right color but was made of wool or a wool-and-silk blend. The name ''jeans'' may have been derived from ''Nimes'' (pronounced NEEMS), but documents prove that blue denim was developed by John Hargrove in late-18th-century Baltimore. The fabric was perfected in the Amoskeag mills in Manchester, N.H., and it was actually from there that Levi Strauss ordered the fabric for his first jeans in 1860.
Levi Strauss & Co. marketed jeans to generations of farmers, loggers, plumbers, and ranch hands as ''sturdy and reliable'' work clothes. In the 1930s, John Ford westerns and California dude ranches popularized the association of jeans and a mythic American West -- and pushed blue denim over into the leisure lives of both men and women.
A May 1935 issue of Vogue magazine instructs women how to wear the new attire: with a ''simply tailored flannel or plaid cotton shirt; a plain silk kerchief, knotted loosely; a studded leather belt; high-heeled Western boots; a Stetson hat; and a great free air of bravado.''
That ''air of bravado'' contributed to jeans' conquest of its next market: would-be rebellious youth. Marlon Brando in ''The Wild One'' (1954) and James Dean in ''Rebel Without a Cause'' (1955) gave jeans a new set of associations and a vast new youth market. In the 1970s, hand-embroidered jeans became the uniform for a new brand of rebellion and personal expression.
High fashion began to take notice. In 1970, French designer Yves Saint Laurent used blue denim in his ready-to-wear Rive Gauche collection. In 1978, American designer Calvin Klein gave jeans a label and a new name, ''Calvins.'' Other designers followed suit: Armani (1981), Valentino (1984), Karl Lagerfeld for Chanel (1984), Moschino (1986), Kenzo (1986), Gianni Versace (1991-92), Jean-Paul Gaultier (1988), Christian Lacroix (1994-95).
Blue denim, concludes the Paris exhibit, had been ''ennobled''; and the designers that adopted it, enriched.
Trends set on the streets
A current exhibit at London's Victoria and Albert Museum takes a harsher view of the link between popular style and high fashion.
''Street Style: From Sidewalk to Catwalk'' documents 45 different street styles and ''styletribes'' -- from Harlem Zoot-suiters in the 1940s to Zazous, Hipsters, Rockabillies, Mods, Rockers, Rude Boys, Hippies, Greasers, Skinheads, Punks, Goths, Rastas, B-Boys, Flygirls, Indie Kids, Grunge, Cyberpunks, and New- Age Travelers. Each style is set in its own cultural context and paired with high-fashion imitators.
Haute couture, such as Dior's ''New Look,'' once set the pace for popular culture, writes the museum's guest curator, Ted Polhemus, in his catalog for the exhibition.
But increasingly, high fashion is borrowing from the streets or, rather, ''exploiting streetstyle creativity.''
''Styles which start life on the street corner have a way of ending up on the backs of top models on the world's most prestigious fashion catwalks,'' he writes.
''Imitation may be the sincerest form of flattery, but just as the counterfeiting of fashion designers' own works undermines their value, something similar occurs when fashion copies streetstyle,'' he adds. ''That authenticity and sense of subcultural identity which is symbolized in streetstyle is lost when it becomes 'this year's latest fashion' -- something which can be purchased and worn without reference to its original subcultural meaning.''
Street style is about what people wear -- berets, beads, sandals, badged denim, baggy pants, painted insignia, metal studs, spandex, rubber, hooded jackets, and gold chains.
It's also about attitude. Marlon Brando's black leather ''Perfecto'' jacket in ''The Wild One'' came to define the born-to-lose outsider with a Bad Attitude. When it shows up in Gianni Versace's Spring/Summer 1994 collection, well, something is lost.
The real thing
Street style is ''authentic,'' Mr. Polhemus insists. ''If today more and more people use their dress style to assert: 'I am authentic,' it is simply evidence of our hunger for the genuine article in an age which seems to so many to be one of simulation and hype.''
In this exhibit, all street styles are viewed as equally authentic, whether inspired by years of immersion in the music and culture of a Harlem jazz club or a glance at the cover of a David Bowie album or an MTV rock video.
The role of the news and entertainment media in amplifying and even creating street styles and the mental attitudes that go with them is at the edge of the exhibit's concerns. It could well have been the focus.
*''A History of Jeans: 1750-1994'' is on exhibit at the Palais Galliera in Paris through March 12. ''Street Style: From Sidewalk to Catwalk'' is showing at the Victoria and Albert Museum in London through Feb. 19.