Urban orchestration: formally imaginative and technically assured, Renzo Piano's s concert hall complex in Rome is also a civic place in the city's best tradition.

Befitting the epithet of Eternal City, Rome has waited a long time for its new Parco della Musica. Renzo Piano's arrestingly zoomorphic trio of scarab-shaped concert halls marks the culmination of a typically protracted Italian saga that began in 1936 with the demolition of the city's original Art Nouveau auditorium housed inside the mausoleum of Augustus. (The Roman remains were subsequently restored as part of Mussolini's hubristic urban remodellings.) There followed a series of aborted plans, stalled competitions and false starts as the design process became bogged down by politics, bureaucracy, finance and the challenge of inserting such a monumental structure into Rome's dense, historic texture. By 1994, an apparently suitable site was selected on the north side of the city, where the nineteenth-century grid of Flaminio meets a disparate collection of sports and object buildings constructed for the 1960 Olympics. Originally a car park for the Palazzetto dello Sport and Flaminio Stadium (both designed by Nervi), even such a seemingly mundane Roman locale yielded up hidden treasures in the form of the foundations of a villa and oil press dating from 6BC, revealed during the course of routine groundwork. This discovery set the project back by a year as Piano reconfigured the site plan to incorporate the archaeological remains within the fan-shaped layout of the three concert halls, as well as providing a small museum to display excavated items.

Other more politically motivated delays also contrived to impede progress, but it is to the credit of both Piano and his patron, Rome's leftist mayor, Francesco Rutelli, that they succeeded in realizing such a challenging civic project. When the complex finally opened at the end of last year, it was greeted with acclaim by performers and public alike -- after nearly 60 years, Rome at last had a centre for classical music that could compete with the best venues in Europe.

The key to the project was Piano's decision to dissect and reinterpret the original programme, which called for a single building housing three auditoria. Instead he proposed three separate entities grouped in a fanlike formation around the fulcrum of a central piazza with ground floor access to a common concourse and promenading staircases servicing each hall. To this trio of small, medium and large sound boxes (with capacities of 700, 1273 and 2756 respectively), Piano also added an open-air amphitheatre in the piazza, capable of seating 3000, which unifies and animates the external realm.

From a distance, the Parco is signposted by swelling, weighty hulks of the lead roofs evoking metaphors of tortoise shells, insect carapaces and the curiously graceful jointed armour of samurai warriors. Continuing Piano's preoccupation with toroidal geometries (perhaps most famously realized at Kansai Airport, AR November 1994), each roof is a fragment of a torus split at its peak for improved drainage. Held in place by steel flanges and lined internally with horizontal planks of pine, the segmented lead roof casings curve out and extend down the flanks of the halls, creating interstitial space for escape stairs. Coated with a pearly protective lacquer, the massive metallic roofs appear to hover over a swathe of newly planted greenery-parasol pines, olive trees and cork oaks-that when fully matured will form luxuriant hanging gardens, as well as a new urban park linking the Flaminio neighbourhood with the Villa Glori to the east.

The Parco complex is approached by a steel and glass pergola lined with shops and restaurants that generate and accommodate daily activity. At this lower level, walls and pillars of thin red Roman brick with travertine flashings suggest ancient ruins denuded of their precious marble. From the central piazza, with its Greek amphitheatre and gardens, glass doors in slender brass frames open onto the crescent-shaped internal concourse, the necklace of circulation that yokes together the concert halls. Sandwiched between the auditoria, the fragments of the Roman villa can be surveyed from the concourse through a large vitrine.

Piano's experience of music theatres and acoustics dates back to the late 1970s when he designed the IRCAM centre for experimental music for Pierre Boulez next to the Pompidou Centre. Since then his repertoire has encompassed concert halls in Venice, Berlin, Turin (Lingotto AR November 1996) and most recently Parma (AR October 2002), all in different ways and on different scales built to serve music both technically and experientially. Here, each of the three auditoria responds to a precise musical configuration. Symphony concerts and major choral works take place in the large hall to the east; ballet and contemporary music in the intermediate central theatre; and chamber music and experimental works in the small 700 seat auditorium on the west side. With its polygonal shape and vineyard terraces of seating arrayed around a central concert platform, the large hail has conscious echoes of Scharoun's Berlin Philharmonie. A sculpted ceiling of glossy cherrywood caissons, suspended from the timber roof structure like some kind of geological formation, is calculated to enhance acoustic performance.

The configuration of the halls evolved initially using models with reflecting surfaces and laser beams to establish graphic representations of acoustic responses. This was followed by computer simulations and physical tests. Cherrywood was selected for the internal linings, based on research into the emission, reflection and reception of sound taking into account different music sources and environmental demands. The richly polished wood has a seductive warmth, resonance and tactility, so that the auditoria resemble the insides of musical instruments. But beyond the technical accomplishment of the halls is a wider social and urbanistic intention to make culture a living part of the city and create new civic gathering places in the manner of other great Roman outdoor rooms such as the Piazza del Popolo and Piazza Navona. Visible from the top of St Peter's, Piano's cluster of musical armadillos marks a bold new improvization on a familiar urban score.

Architect

Renzo Piano Building Workshop, Genoa

Structural engineer

Ove Arup & Partners, Studio Vitone

& Associati

Services engineer

Manens intertecnica

Acoustic consultants

Muller Bbm

Landscape consultants

F. Zagari, E. Trabella

Photographs

Paul Raftery/VIEW