Composer: Marco Beltrami
From Wiki:
I, Robot is a science fiction film set in a world where humans and humanoid robots interact (Chicago in the year 2035). It was directed by Alex Proyas, written by Jeff Vintar, and starred Will Smith. It was produced in the United States, filmed in Vancouver, British Columbia, and released on July 16, 2004.
Marco Beltrami, composed the original music film score "with only 17 days to render the fully-finished work." It was scored for 95 orchestral musicians and 25 choral performers with emphasis placed on sharp brass ostinatos. Beltrami composed the brass section to exchange octaves with the strings accenting scales in between. This technique has been compared as Beltrami's "sincere effort to emulate the styles of Elliot Goldenthal and Jerry Goldsmith and roll them into one unique package." Take for example the Tunnel Chase scene, which according to Mikeal Carson, starts "atmospherically but transforms into a kinetic adrenaline rush with powerful brass writing and ferocious percussion parts." Also, the Spiderbots cue highlight's ostinatos in meters such as 6/8 and 5/4 and reveals "Beltrami’s trademark string writing which leads to an orchestral/choral finale." Despite modified representations of the theme throughout the movie, it's the end credits that eventually showcase the entire musical theme.