Spain may be the best microcosm of architectural trends in the world today. Spain has it all: a massive inflow of money, a chic reputation, and, since Frank Gehry’s Guggenheim Museum in Bilbao, demonstrable proof of new architecture’s efficacy in generating tourist dollars, thus aiding what has been since the Franco years (1939-1975) Spain’s most important industry. Terence Riley’s last show as the Philip Johnson Chief Curator of Architecture and Design at the Museum of Modern Art is “On-Site: New Architecture in Spain,” on exhibit until May 1st.

Walking through the exhibition, I could not help thinking of a 1930 essay by Lewis Mumford, “The Wavy Line versus the Cube.” Mumford wrote that modern architecture, since its inception, had been, and would continue to be, a battle for the upper hand between the wavy line, growing out of Art Nouveau, and the cube, growing out of Cubism. When we think of Spain’s titanic cultural figures of modern art, we inevitably think of Picasso and Antoni Gaudi. Both can be viewed at MoMA, and to do so is an excellent thing after seeing “On-Site.” The contemporary architecture of Spain casts into sharp relief the distinction between the wavy line and the cube. Mumford said that a fundamental difference between Art Nouveau and Cubism was that the former sought to transmute materials into naturalistic forms whether or not the material was naturally pliable, while the latter sought to employ materials and technological processes in what were perceived to be their own quintessential terms. What Mumford did not foresee was that technology itself would dissolve into the wavy line, wherein, I would suggest, lies the unexampled if as yet completely unrealized artistic potential of the new millennium. The “machine aesthetic” means something radically different in 2006 from what it meant in 1930.

We see the New Age machine aesthetic in the works of the two architects whose names come most readily to people’s minds these days in connection with Spain: the American Frank Gehry and the Spaniard Santiago Calatrava. Both are architects whose works have grown out of computer-aided design and the unprecedented ease with which complex mathematical equations can be solved in the engineering process. I have always thought of Gehry in his Bilbao mood as childlike in the glee with which he designs certain forms because, well, he can. Gehry, or rather Gehry Partners, is represented in “On-Site” with a project for a hotel at the Marques de Riscal Winery in the Rioja, the great wine region in the Basque country. The Bilbao museum has always reminded me of two things: those Las Vegas compactions of cities – in this instance of a mythical Italian hill town comprising several leaning towers – and Picasso paintings like “Three Musicians,” in MoMA. Its occasional waviness notwithstanding, I think of the Bilbao museum as essentially a cubistic work. But I prefer the winery hotel,which is Gehry in his flowing silver ribbons mood. It makes me think of Christmas in California.There is to my mind, at least, in Gehry’s work a vigorous expression of the cultural mutations growing out of American Sunbelt sprawl. That said, there is also in the winery hotel an obvious connection to the wavy line of Art Nouveau, though nothing – in any of these projects – that has the majestic sinuosity of Gaudi’s grille from the Casa Mila (1906-12) on exhibit in MoMA’s architecture and design galleries. Of Calatrava, alas, there is nothing in the exhibition. That said, he has hardly been neglected of late.

As Terence Riley notes in the splendidly produced catalogue, while several factors have converged to make of Spain the architectural hot-spot of our time, perhaps the most notable has been Spain’s 1986 entry into the European Union, which not only betokened Spain’s emergence as a modern democracy following 36 years of rule under Francisco Franco but also brought in lots of money. Mr. Riley notes that under EU programs of wealth transfer from richer to poorer member countries:

Spain has received nearly $110 billion in funding over the last twenty years toward the construction of new highways, bridges, railroads, train stations, airports, and more, making it the largest net receiver of any EU member. … In the last twenty years the country has undertaken the most extensive building and rebuilding of its civil infrastructure since the Romans unified the Iberian Peninsula with roadways and aqueducts during the reign of Augustus.

One is stunned walking through this show at how much of it is “civil infrastructure”- nearly all of it.Paramount among this infrastructure is the massive new set of terminals at Madrid’s Barajas Airport, which, as Mr. Riley points out, was until recently the largest construction site in Europe.The architects were London’s Richard Rogers Partnership and Spain’s Estudio Lamela. Set to open later this year, the terminal interiors feature dramatically undulating ceilings that sweep upwards to form shallow domes with skylight-oculi.

Even the rather spectacular Barcelona skyscraper by Jean Nouvel was not built for a private corporation, but for the city’s water company.There are a couple of private houses and a chapel.

As for the rest of the 53 projects covered, we have stadiums, airports, museums out the yazoo, municipal theaters, government housing projects, parks, health centers, municipal or state office buildings, town squares, schools, and libraries. The only private buildings of scale are hotels.

Of the 53 projects, 35 are currently under construction, and are represented in the exhibition by models, most of which, qua models, are not very good. That is, they give very little sense of what the building will look like. For the 18 projects that have been completed, MoMA has commissioned Roland Halbe to make large-scale, sometimes quite effective photo murals. The models and murals supplement drawings, plans, and wall texts in a layout that is quite eye-catching but also confusing in that it is sometimes difficult to relate models and murals to their corresponding wall texts and drawings without encountering other projects in the interim,thus breaking the continuity.It is very hard to lay out a show in which materials relating to a specific project are in different media with different display requirements.

Just as we think of Gehry and Calatrava when we think of architecture in Spain, so in “On-Site” do we have a combination of Spanish architects and architects from abroad. Foreign contributions besides Rogers’s include Jurgen Mayer H.’s strange Metropol Parasol in Sevilla’s Plaza de la Encarnacion; Foreign Office Architects’ Municipal Theater and Auditorium in Torrevieja, Alicante; Jean Nouvel’s aggressively cubistic Museo Nacional Centro de Arte Reina Sofia Expansion in Madrid, and his Torre Agbar in Barcelona; Toyo Ito’s aggressively wavy, by turns interesting and vaguely creepy Relaxation Park in Torrevieja, Alicante; Dominique Perrault’s Tennis Center in Madrid; the expansion of the Institut Valencia d’Art Modern by Kazuyo Sejima (an architect whose career Mr. Riley has done much to promote) and Ryue Nishizawa; Herzog & de Meuron’s La Ciudad del Flamenco in Jerez de la Frontera, Cadiz; Rem Koolhaas and Ellen van Loon’s Congress Center (yawn) in Cordoba; Zaha Hadid’s Euskotren Headquarters Development in Durango, Vizcaya; MVRDV’s Edificio Mirador in Sanchinarro, Madrid; and 2005 Pritzker Prize winner Thom Mayne’s public housing project in Carabanchel, Madrid. Of these, I find Nouvel’s Barcelona skyscraper, inevitably referred to as phallic, and Toyo Ito’s Relaxation Park to be the most intriguing projects. The Nouvel building continues that architect’s adventures in glass; a skin of aluminum is shaded in a spectrum of 25 colors, covered by glass of varying degrees of transparency. When lit up at night, it looks like a multi-flavored popsicle.

Few of the Spanish architects in the show have attained star-chitect status. An exception may be Rafael Moneo, architect of the Catholic cathedral in Los Angeles. His town hall extension in Murcia is a crisp modernist design recalling the work of the Italian Giuseppe Terragni. It is meant not to compete with Murcia’s magnificent cathedral, which is directly across the square, but rather to blend in (by among other things using a mellow sandstone rather than concrete) and through its slitted-screen facade to frame views of the square. The other Spaniards are not as well known, at least not here. Enric Ruiz-Geli’s Hotel Habitat in Barcelona is a cuby building draped in a web of 5,000 light-emitting diodes powered by photovoltaic cells. Enric Miralles and Benedetta Tagliabue designed the Santa Caterina Market renovation, also in Barcelona, in which an old, large, classically designed, arcaded market hall is roofed by undulating sheets of tiles in a rainbow of exuberant pinks, yellows, greens, yellow-greens, purples, and oranges. Jose Antonio Martinez Lapena and Elias Torres Tur designed the Granja Escalators in Toledo. To relieve the automotive congestion in the old capital, the architects cut a 90-foot-high structure comprising a six-stage escalator into the city’s medieval wall and a neighboring hill. At its bottom is a car park. Thus one can park outside the city wall, and ascend to the city to continue on foot.

Last but not least, “On-Site” is, as I noted, Terence Riley’s last show as Chief Curator. In March he becomes director of the Miami Art Museum. He has held his present position for the last fourteen years, and is only the seventh architectural curator MoMA has had. He was responsible for the major Frank Lloyd Wright exhibition in 1994, and played an important role in MoMA’s massive expansion designed by Yoshio Taniguchi. Mr. Riley has said in interviews that he was never so happy as when he worked on the expansion, and we wish him well as he soon shall oversee a similar expansion in Miami.

fmorrone@nysun.com

Until May 1 (11 W. 53rd Street, between Fifth and Sixth Avenues, 212-708-9400).