What makes a composer a composer? The week that has caused this to cross my mind has taken in both Edgard Varèse and Howard Shore. These are very different composers writing different music at either end of the 20th century. What unites them is a strong, progressive visual sense to their music: Varèse was involved in experimental film as an actor and had a strong, possibly synaesthetic sense of his vision of his music; Howard Shore is a composer of film scores. It's unsurprising then that both men seem to be interested in sound design as part of their function.
But is it the composer's job to imagine new sounds, whether it be to fit a given vision or whether it's to try and crystallise a sound they have in their head in a manner that can be reproduced outside of that head (!)? Or is the composer's job a more formal, overdetermining function - to provide a framework to be interpreted by performers?
Varèse provided tape recordings of the music that he wanted in a concert but is this composing or is some other art, more akin to sculpture? The anthropologist David Fanshawe is famous for having written and collated a work called African Sanctus that is an original score juxtaposed with recordings he made whilst on his travels. Clearly this man is both, scientist and composer. Is Varese then scientist and composer? Certainly he was fascinated by scientific investigation which found its way into musical recreation in pieces such as Arcana.
Similarly it was sometimes a moot point where the sound design of The Two Towers ended and the score began. Yet Shore's cues - precise though they are - are clearly musical cues, of a part with the emotional and narrative warp and weft of the story, not recreations of acts of the characters on screen. For all that synchronising the music with the screening was kept in metronomic check, the performers still had autonomy over the music's performance.