BARCELONA, SPAIN — 'BARCELONA, posa't quapa."In English, the phrase means "Barcelona, make yourself beautiful." But to the inhabitants of this ancient city, the campaign to clean away the soot of centuries has become synonymous with Catalan nationalism. Though it may seem that hosting the 1992 Summer Olympic Games was the catalyst for wide-ranging construction and rehabilitation activities, Barcelona's rejuvenation had begun several years earlier. Selection in October 1986 as an Olympic site consummated the first phase of a resurgence that commenced in the early 1980s. Barcelona's transformation owes to the vigorous revival of Catalan culture and language since the death of Gen. Francisco Franco in 1975, and to the adoption of a new Constitution in 1978, which gave Spain's regions greater autonomy. Indeed, as 1992 nears, the slogan, "Barcelona, make yourself beautiful," is being replaced by posters whose message emphatically declares that "Independence is possible." The emergence of Eastern European nations and the recent international recognition of the Baltic republics have given further encouragement to Catalan separatist longings that go back many centuries. Another motto, "Barcelona, city of the future," liberally employed in publicity for the Olympic Games, has special connotations. Residents see Barcelona arising from a decade-long economic revival project looking appropriately like a world capital. "We know we're not London, Paris, or Rome," one government official confided, "but we're trying to find out if we might be Athens or Brussels." The Olympics have come to be understood as the prime opportunity to beam the region's unique cultural identity across the world as part of extensive media coverage that will accompany the games. Unquestionably, many of the physical improvements being made to the city will directly serve the crowds gathered for the Olympics. The Montjuic Stadium overlooking the city has been renovated and enlarged. El Prat de Llobregat Airport is being expanded, and new hotel space is being built, which should alleviate a notorious shortage that sometimes forced tourists into housing well outside the city along the Costa Brava.Despite Barcelona's emphasis on its Catalan heritage, there has been little chauvinism in the choice of architects and engineers for the various building projects. El Palau Sant Jordi, a domed indoor sports arena, was designed by Japanese architect Arata Isozaki. The 260-meter communications tower on the Collserola hillside was drafted by Norman Foster of Britain. Improvements made for the Olympic Games have been devised in such a way that they will enhance city life well after the athletes depart. Integrated into the Olympic plans are ventures to revitalize the harbor area, invigorate neighborhood life, and improve public transportation. For example, completion of a ring road around the city should mitigate the amount of traffic that has had to move through the central city, and help to decrease Barcelona's epic air pollution. In addition, the GEC (Grans Equipaments Culturals) initiative, popularly called the Cultural Olympics, has taken as its goal the positioning of Barcelona as a European cultural capital. The emphasis on quality-of-life projects, which may encourage future tourism as well, is evident in the creation of new urban spaces, especially in the older sections of the city. Numerous vest-pocket parks and plazas, which serve as community gathering spots, now allow light and air to penetrate into the densely packed old neighborhoods. As the plazas have been completed, fresh vistas have opened up for city dwellers and tourists alike. The priority given multipurpose civic spaces is apparent in the changes to the area in front of Barcelona's cathedral. With traffic rerouted and the square enlarged and repaved, the building's imposing and elegant Catalan gothic exterior can now be fully seen. Moreover, the expanded plaza provides additional room for the performance of the sardana, the national dance of Catalonia, traditionally presented there every Sunday. With more than 300 projects underway throughout the city, it is impossible to avoid the rattle of jackhammers and the rhythmic click of cranes changing position over construction sites. In the Parc de la Ciutadella, work on the formidable "great fountain" has just been completed. Visitors to the Picasso Museum, which holds a great deal of his juvenilia, along with much admired blue-period works like "La Vie," must use an alternative entrance while the old palaces that house the museum are refurbished. Topping the list of national treasures under restoration is the Museu D'Art de Catalunya, which has been closed for nearly three years. Perhaps the most indicative new project is the huge complex known as the Centre de Cultura Contemporania, which blends existing architectural treasures with postmodern buildings as an expression of the persistence of the past in Barcelona's future. Traffic jams occurring on the first day of school this September were said to owe to the fact that city residents, returning from coastal vacation spots, had not yet learned the new street configurations. Oddly enough, there is little grumbling about the inconvenience or the expense. Along La Rambla, Barcelona's broad promenade, where vendors sell Barcelona '92 paraphernalia, one can find the occasional dissenting T-shirt showing the Olympic's cartoon mascot, COBI, looking destitute, with his trouser poc kets turned out to indicate impoverishment. Below COBI are the words, Barcelona 1993, a not-so-subtle reference to the fact that many Olympic host cities have lost money. But for the most part, Barcelonans accept the price of being up-to-date as the cost of securing national identity within the European community. Of course, this is not the first time that modernization and Catalan identity have combined. At the turn of the last century, the Renaixenca or rebirth of Catalonian culture caught up all the arts. A distinctive Catalan architecture matured in a period of economic development that saw the growth of Barcelona's industrial base, especially its famous textile mills. Then as now, modernism was equated with a nationalistic pride of place. Many of the buildings constructed during the Renaixenca have been or are being refurbished during this second renaissance. The monument to Christopher Columbus, erected for the Universal Exhibition of 1888, has been cleaned and the area adjacent to it widened. The stained glass and mosaics of the Palau de la Musica Catalana, the lush concert hall designed by Lluis Domenech i Montaner, have regained their 1908 shimmer. The first Barcelonan renaissance was characteristically associated with the achievements of Antoni Gaudi (1852-1926), the highly imaginative Catalan architect, sculptor, and ceramicist, who was born in Reus, near Tarragona. His works are among the most likely to be slated for reconditioning. In the Parc Guell, high above the city on Carmel Hill, the quiet is interrupted by the tinkling tap of workmen's hammers. The vividly colored ceramic inlays on the bench that Gaudi used as a balustrade above his densely columned, would-be market building are being restored. The section of the bench that has been finished looks like a bright custard ribbon liberally strewn with variegated sprinkles. Apartment buildings fashioned by Gaudi, like the cement and ironwork confection, Casa Mila (1905-1910), still resound with the architect's audacious embrace of Modernism. Yet it is Gauds La Sagrada Familia, the Church of the Holy Family, which has functioned for decades as the symbol of Barcelona and the spirit of Catalan resolve. It is difficult to tell which of the cranes aloft the bell towers of La Sagrada Familia are part of the more or less permanent reconstruction efforts at the church, and which are being used to make a new plaza behind the building. Plans for the immense, unfinished (and possibly unfinishable) church were created by Gaudi as the ultimate orchestration of his architectural knowledge, design philosophy, and spiritual faith. Woven into the iconography of the church is the idea of resurrection, expressed through the soaring verticality of its towers. Today, the slender lattice work of tall cranes amid the openwork of La Sagrada Familia's spires maintains the theme of resurrection. More than simply preparation for the 1992 Summer Olympic Games, the spectrum of the old and the new in the Barcelona skyline has come to embody what Jordi Pujol i Soley, president of the Generalitat de Catalunya, has called the Catalan "struggle of hope."