Some ancient cosmologists included the fifth element in their interpretation of the structure of nature, which they called the quintessence or aether – the hypothetical invisible matter that fills the universe.
Conversely to Fire, Earth, Air and Water, which are earthly and, as such, decaying elements, the fifth element consists of a different, permanent matter. As a consequence, it has a large number of various interpretations, and the listeners at each of the five thematic concerts of the Belgrade Philharmonic Orchestra can identify one of those interpretations – love, metaphysics, science fiction, power on earth and supernatural phenomena.