Bayan Northcott speculates on the sonic perplexities of the forthcoming Millennium Dome
It was 12.30pm on 29 March 1871 and all was set for an eminently Victorian occasion. The Queen, though still in mourning for her Albert fully 10 years since his death, had declared that the grand new edifice looked "like the British Constitution", and a vast gathering had converged on Kensington Gore for the opening ceremony. But when the Prince of Wales stepped before the orchestra to deliver his welcome address, "speaking distinctly in a clear voice that could be heard in all parts of the building" ran a report, "in many parts it could be heard twice..." The Royal Albert Hall's dreaded echo, which was to take almost a century of tinkering to tame, had declared itself.

It might seem surprising that the designers were caught out so badly, if only because they must have know about the sonic vagaries of such domed structures as St Paul's Cathedral, or the Reading Room at the British Museum. True, some of London's most memorable music-making back in the previous century - including appearances by Handel and the young Mozart - had also been heard in a large, curved space: the Rotunda in Ranelagh Garden, which measured no less than 150 feet in diameter. But that was essentially an assembly room to walk about in, and doubtless those who wished to follow the music in more detail through the reverberance of chattering simply stood nearer the orchestra. Reverberance? Or are we dealing here with an ominous pre-echo? For amid all the information and uplift that has been proclaimed over recent days about the forthcoming Greenwich Dome, one question has gone strangely unasked, let alone answered: does anyone know, does even the structure's eminent designer Sir Richard Rodgers have any clear idea, what the Millennium Experience is going to sound like?

One of the basic decisions in enclosing any acoustic space is what to do about potential sound penetration from outside. The Millennium Dome is being constructed close to the Blackwall tunnels and little more than a mile to the south west of the City of London Airport. It is to comprise an enormous Teflon-coated tent roof covering 20 acres and slung on hawsers between 12 huge Skylon-shaped and outward-leaning steel gantries, which will actually pierce the roof within its circumference. While it is inconceivable that the designers will not have foreseen and forestalled the possibility of the gantries and hawsers picking up ground vibrations or thrumming in high winds, the sound of heavy rain or hail on that vast expanse of roof can only be imagined. Presumably some sort of at least partially sound-insulating inner lining will have to be added to the roof, which in turn may condition the acoustics, depending upon whether it tends more to absorb or to reflect the sounds from beneath.

Hemispherical domes with hard inner surfaces are notorious for focusing the sounds below in small areas while weakening and dispersing them all round. If a building is large enough for there to be a perceptible lag between direct and reflected sound, this unevenness is likely to be compounded by echoes - while in the Royal Albert Hall these phenomena are further complicated by the fact that the building is not circular but elliptical. At least the Millennium Dome is to be circular, and while vast enough to contain the Royal Albert Hall several times over with the Rotunda thrown in, its comparatively shallow shape may prove to distribute sound rather more evenly. All the same, one wonders whether the sudden announcement of an additional baby dome alongside for live performances reflects uncertainty about how manageable the sound environment of the parent dome may turn out. And, of course, there remains the not-so-little consideration of the sonic effect of its contents.

For, as we now know, the exhibition is to take the form of 12 Themes all arranged around a central arena. The latter will now present an audio- visual spectacular designed by Mark Fisher, who does sets and lighting for Rolling Stones tours, six times a day and doubtless generating many decibels. And given modern society's general horror of life without background music, one may expect that each of the thematic zones will be contributing its own distinctive sounds - whether computer-game jingles and explosions from the futuristic classroom workstations of the education zone horribly entitled Licensed to Skill, or the purling of living waters and faith minimalism from the 2,000-year trek through religious history of the Spirit Level zone.

Could it even be that, relinquishing any attempt at sound control, the planners will be content to let all these sources contend with one another? Such an anarchy of sound might at least have the advantage of masking any acoustic problems of the structure itself, though it would also necessitate some pretty drastic local sound proofing if, for instance, the calm of the proposed meditation area in the Spirit Level were to be preserved, or the ghost-train intensities of the fantasy trips through the Dreamscape zone were not to be dissipated by more mundane noises from elsewhere.

Is there any alternative? Well, there could have been, had Britain, for better or worse, more of a commitment to what might be called command- aesthetics in the French tradition of grands projets. One thinks of the Philips Pavilion at the Brussels Expo 1958, conceived by Le Corbusier, designed by Xenakis and housing a specially composed Poeme electronique by Varese; or of Stockhausem's spherical auditorium for the 1970 Osaka World Fair, in which he sat at a central control desk mixing the signals from solo players around the periphery and projecting them in parabolas and spirals of sound about the heads of his audience. But those were projects for a time in which modernism, if not understood, was still generally believed to point to the future, whereas, amid today's contentious relativity of trends and values, one can only imagine the outrage of large sections of the public were the Dome to be given over to some sternly primitivistic soundscape by Sir Harrison Birtwistle; or the hopeless groans of others (this writer included) were it consecrated to the soupy reassurances of Sir Andrew Lloyd Webber.

And maybe, just maybe, the whole thing will muddle its typically British way through and more or less come out right. Maybe the thinness of the Dome's roof will preserve a relatively outdoor acoustic, in which the sounds of individual presentations will dissipate without unduly interfering with each other. Maybe someone in the Government will recall that the arts of the past 2,000 years, not least in Europe, have thrown up the odd manifestation of significance, and a few concerts in the baby dome might be given over to a recognition that the present century of British composition has been, and continues to be, as diverse and brilliant as any since at least the Baroque. And maybe whoever is writing this column in 22 months' time, when the Millennium Experience has finally opened, will be able to show that the forebodings in the present article were as risibly wide of the mark as such aesthetic prophecies almost always turn out to be.