Editing To Fly! (section)

=== Post-production ===
[[File:IMAX split screen mattes revision.jpg|alt=A square split equally to nine, with an X denoting center of attention at the lower center. Another square has bars above and below, only split to six with the X put higher up|thumb|upright=1.5|Illustration of the new [[Matte (filmmaking)|mattes]] for the multi-image scenes]]

''To Fly!'' was edited by MacGillivray and Freeman, with [[Alexander Hammid]] supervising, using a [[Moviola]]. Knowing they would experiment with the editing, the film's shots were directed beforehand to allow them to do so. The pacing of the shots was designed so that audiences can explore the entire IMAX screen. The 35&nbsp;mm opening where Ezekiel is still at ground is [[Windowbox (filmmaking)|windowboxed]] to 1⁄6th of the screen; as he ascends, the scene [[Smash cut|smash]]-[[Dissolve (filmmaking)|dissolves]] and the whole screen is filled, intendedly to intensify the scene's mood and as a reference to aviation, which the narration calls "like the opening of a new eye".<ref name=":8" /> This was inspired by the opening scenes of ''[[This Is Cinerama]]'' (1952) and the first ever IMAX film ''[[North of Superior]]'' (1971).<ref name=":12" />

The placing of multiple images on the same screen were occasionally used; these were inspired by the multi-image films ''[[In the Labyrinth (film)|In the Labyrinth]]'' (1967) and ''[[Tiger Child]]'' (1970), made by IMAX's precursor Multiscreen. In one scene of the Blue Angels, the screen divides into 36 duplicates of the same shot. With IMAX screens having a different focus center, thus making an evenly-divided multi-image scene confusing for audiences, Jim Liles of the [[Optical printer|Optical]] Department at [[Metro-Goldwyn-Mayer]] and filmmaker Dennis Earl Moore designed new [[Matte (filmmaking)|mattes]] in which the bottom row is 15% larger than the top. Smith supervised the curation of archival and original footage to be incorporated into these scenes. After four months of editing, two [[Norelco]] AAII 70/35&nbsp;mm projectors were installed to preview in the highest quality possible.<ref name=":8" />

MacGillivray chose the [[film score|film's score]] to be composed and conducted by [[Bernardo Segall]]. It was performed by a 49-piece [[symphony orchestra]] at [[the Burbank Studios]] which he considered "the most professional and experienced" in California that he could find. Segall's works were described by MacGillivray as having "an air of sophistication and elegance, which would maintain the steady rhythm and pulse of the film".<ref name=":8" /> The score was the first in history to use a [[keyed bugle]], which is also depicted in the film's opening scene: at the gathering for Ezekiel's ascent, a small [[fanfare band]] plays a [[Fife (instrument)|fife]], drum, clarinet, and [[B♭ (musical note)|B♭]] keyed bugle.<ref>{{Cite book|last=Dudgeon|first=Ralph Thomas|title=The Keyed Bugle|date=October 20, 2004|publisher=[[Scarecrow Press]]|isbn=0810851237|edition=2|location=[[Metuchen, New Jersey]]|pages=134|chapter=The Revival|oclc=1285644620}}</ref> The score was then [[Music editing|edited]] by Richard R. McCurdy and [[Music mixing|mixed]] by [[Dan Wallin]]. It was recorded in [[Multitrack recording|16 channels]] and then [[Mixdown|downmixed]] to three of the six channels on a 35&nbsp;mm [[sound follower]], which would play in sync with the picture in theaters.<ref name=":8" />

Sound design was done at [[Todd-AO]]'s [[Hollywood, Los Angeles]], studio.<ref name=":4" /> Sam Shaw edited the sound effects while [[Ray West]] and Jack Woltz mixed them. Some scenes in the film were made solely to exploit IMAX's sound technology. For example, a multi-image scene in which two jets cross each other uses the [[Surround sound|surround]] nature of the sound system; MacGillivray expected audiences to "shiver" due to the dramatic shift of attention. In the train screen-hitting shot, the horn and engine noise gradually surround the audience.<ref name=":8" /> [[Don't Go in the House|Joseph Ellison]] also helped with the sound design,<ref>{{Cite book|last=Edwards|first=Matthew|title=Twisted Visions: Interviews with Cult Horror Filmmakers|date=June 19, 2017|publisher=[[McFarland & Company]]|isbn=978-1476628141|location=[[Jefferson, North Carolina]]|pages=66|chapter=Don't Go in the House: An Interview with Joseph Ellison}}</ref> which completed on June 18, 1976.<ref name=":12" /> After post-production, which—combined with the space sequence production—took six months, Conoco applauded the film's [[rough cut]]. The company's investors and the Smithsonian gave input for the final cut,<ref name=":8" /> which spanned more than {{Convert|8,000|ft|m|abbr=none}} of film stock.<ref name=":50" />