The interval came and two thirsty concert-goers in the huge balcony of the biggest of the three so-called beetles that make up Romes new music auditorium wanted a drink. To their astonishment, a uniformed attendant told them the balcony was without a bar but politely led them to a small, unmarked lift and accompanied them to the first-floor stalls and then down a slippery flight of wooden steps to a velvety rope staffed by two flunkies who handed out passes.

A swift hike followed. A bar hove in sight and so did drinks, but the attendant remained there, lurking in the background like a minder in the old Soviet Union. Just as well, because the warning lights were flickering already. The minder led a brisk trot through a dizzying labyrinth back to the rope and then up to the concealed slow lift, but to the wrong sector of the balcony; and so there were spurts of sprint to locate the right door. This was smartly closed behind the two just as the conductor raised his baton for the second half.

Since the ultra-modern auditorium opened last year complaints have poured in, especially from older people, about its surprising lack of lifts and balcony loos, and the long queues in front of the too few toilets in the foyer. But Goffredo Bettini, a 51-year-old former communist party leader who now heads Musica per Roma, the company in charge of the Music Park, has promised big changes by this September. These will include two fast, 15- to 20-capacity, foyer-to-balcony lifts designed by Renzo Piano himself, the famous Genoa-born architect behind the auditorium, a place cloaked on the outside by sound-proof lead and upholstered on the inside with American cherry wood, hard-baked brick and travertine marble, adorned with baffles, known as the potato crisps, suspended from the roof. It seems Piano initially skipped lifts and loos out of anxiety to get the place finished in time.

But balcony-goers who need a glass of water or beer, or even a coffee, will have to remain thirsty. No bar, it transpired, will ever materialise. The explanation came from the head of the press office, a young woman who refused to be named. This is a structure of great prestige, she said. We cant have bars all over. Its not a cinema.

The only consolation for the dry-throats, according to the leader of one of the much sought-after guided tours (taken by 27,000 people between January and March this year), is that, acoustically, the best seats in the whole hall are in the balcony, especially close to the roof, although the most expensive seats are down in the stalls. Were still in the 19th century from that point of view, he joked. People still like to dress up and be seen.

Acoustically the auditorium, lost in greenery close to the old Olympic Village in the Flaminio district, has been praised to the skies, as Piano hoped it would be. Building a concert hall, he explained, was as exciting as trying to make the perfect violin. The final sound was everything, and all had been subordinated to it weak bladders included. But apparently perfection has not been reached just yet. Luciano Berio, a modern composer and superintendent of the Accademia Nazionale di S. Cecilia, the parent of Romes oldest and foremost in-house orchestra, whose new home is the auditoriums 2,800-seat Sala Grande, judges that because of its novelty, beauty and technical complexity, the hall still needs running in, and that before September the stage needs altering to afford the orchestra more flexibility. But he also struck a note of fatality: Music and Renzo Pianos conception of acoustics and architecture are not for everybody.

Everybody includes an assiduous and tuned-in Australian concert-goer, who after one visit found the acoustics so impeccable that what he called the defects of the S. Cecilia Orchestra, comfortably muffled in their old concert-hall in Via della Conciliazione, now stood out a mile, with the result that he vowed never to set foot in the place again.

Aesthetically, the impact of the place has left many Romans dumbfounded. An Abacus survey showed that 42 per cent of them greatly approved of it, finding it una struttura molto importante. But the beetles struck a 27-year-old on one of the tours as stranded turtles. His girlfriend said she couldnt make up her mind what to think. To an English journalist, they looked like unfinished hangars; somebody else took them for walls of death for mad bikers, and a youth was heard fantasising about sinister secret space stations that had touched down in the steppes of Russia.

So far, the auditorium has been 80 per cent full on average. In March the pop singer Ligabue pulled in 95 per cent of capacity, though even then, recalled Jurgen Reinhold of the acoustics firm in charge, an exceptional effort had to be made to get things just right, and similar preparation would be needed for all future special events.

It seems the auditorium is as delicate as any instrument in the many orchestras it is destined to welcome.

Auditorium Parco della Musica

Viale P. de Coubertin 30. For information and tickets tel. 0680242350/1, www.auditoriumroma.com (also on-line bookings). 11.00-18.00. Wednesday closed.

Getting there: Tram number 2 from Piazzale Flaminio to Piazzale Apollodoro (the stop after Flaminio stadium). From here it is a five-minute walk. Bus number 910 and the new M line from Termini station also pass the complex.

Services: ReD, which stands for restaurant and design, is the elegant on-site eatery. Here you can not only eat, drink and admire the decor, but also buy furniture and accessories. Open lunchtime until late, tel. 0680691630, www.redrestaurant.it.

NoteBook is a book shop where you can purchase CDs by artists that have performed at the Auditorium, as well as music and art-related books and DVDs. Open daily, tel. 0680693461.

BArt is the elusive bar, with drinks, snacks and a Sunday brunch. Open daily 10.00-18.00 and during performances.

Picture: The inside of the Sala S. Cecilia, the largest of the three concert halls at the Auditorium-Parco della Musica.