Director Tony Scott's Unstoppable is an action thriller about a runaway train full of hazardous materials and the people who try to stop it from creating a disaster, and Harry Gregson-Williams' score naturally follows the contours of the editing, sometimes suggesting the concerns of the heroes (Denzel Washington and Chris Pine), sometimes accompanying the train on its headlong journey. To do so, Gregson-Williams employs a string orchestra consisting only of violins, violas, celli, and basses, which mostly content themselves to provide wistful, somewhat ominous figures in support of the real engines of the music, the synthesizer sounds dominated by pounding percussion. Within individual cues, Gregson-Williams often goes back and forth, for instance in "Are You In or Are You Out?," alternating between the rapid electronic beat sections and brief slow interludes of strings to conform to the film's cutting. The action lets up only with the final cue, "Who Do I Kiss First," underlying the end credits, by which time that unstoppable train finally must have been stopped.
AllMusic Review by William Ruhlmann