Requiem for a Tower
From Tolkien Gateway
Requiem for a Tower is the name for the up-beat song present in a trailer for Peter Jackson's The Two Towers. The song is one of the most memorable tracks from Peter Jackson's films but unfortunately was not even originally created for the movies, but was the main theme for the Requiem for a Dream (2000) film.
For the trailer however the song was re-orchestrated by The Ant Farm with three composters (Simone Benyacar, Dan Nielsen and Veigar Mairgersson), forty musicians and twenty choral voices.