Giacchino noted that recording in the 1960s was largely different than modern day recording and Dan Wallin, the recording engineer, said that Bird wanted an old feel, and as such the score was recorded on analogue tapes. Wallin noted that brass instruments, which are at the forefront of the score of The Incredibles, sound better on analog equipment rather than digital. Wallin came from an era in which music was recorded, according to Giacchino, "the right way," which consists of everyone in the same room, "playing against each other and feeding off each other's energy" Tim Simonec was the conductor/orchestrator for the recording of the score.
^Brad Bird, Michael Giacchino et al. (2011). The Incredibles. Special Features - Behind the Scenes - More Making of The Incredibles: Music (Blu-ray Disc). Buena Vista Home Entertainment.CS1 maint: Explicit use of et al. (link)