What form should one use to enhance to the utmost the brilliance, harmony and depth of sound from a symphony orchestra? Is there perhaps an ideal form on acoustics grounds for a drama theatre for Shakespeare’s plays? Such questions must have inspired many of the more original solutions to the auditorium problem. A particularly appealing approach for instance, especially for those sensitive to the charms of classical architecture, is that certain ratios of proportion are propitious. The argument runs that since our ears appreciate harmony and harmony is based on simple proportions, so buildings to support harmony should likewise be built with favourable ratios of proportion. Sadly this charming argument is fallacious since the actual dimensions are also relevant. This means that a concert hall with preferred proportions would only be suitable for one musical key, a concert hall in C perhaps? However there is the further point that the dimensions of auditoria are in any case too large for such considerations to be significant; we can fortunately design halls for all keys.