The Fifth Symphony's local details become clear only when considered within the workings of a single purpose being pursued throughout all of the movements. This is a truism for grasping symphonic works in general, but nowhere is it more critical than in this work. Here the sheer burden borne by the ideas demands such an approach, for these ideas are now claimed to generate the non-normative, ad hoc architecture (‘content-based form’). If we wish to perceive these unconventional aims, it can be useful to leave some of our conventional expectations behind.

One may consider the symphony's tonal planes, for instance, as slow, ‘protominimalist’ transformation processes. As a whole the work may be heard as a prolonged E♭-major sound sheet set into hierarchies of surface and subsurface motion – as a vast reflection on the symphonic sonority (Klang) of the E♭ tonic chord. This is the centre of gravity, from which colouristic excursions onto secondary (non-dominant) sonorities are launched, but back into which they inevitably fall. Sibelius illuminates the symphony with only five ‘tonal colours’: E♭, G, B, C, and G♭. In the first movement the gravitational centre, E♭, is attracted to two other secondary sonorities whose roots are a major third above and below, G and B (thus equally dividing the octave by major thirds).