To clarify some questions raised by other user comments, I quote from the liner notes to a CD collection called "Classic British Film Music," which includes a suite from the score Arthur Bliss composed for the original version of the film:
"CONQUEST OF THE AIR was planned as an epic chronicle of mankind's romance with flight from the early legend of Icarus to speedy aerial circumnavigations of the modern age. This history was to be retold as a series of lavishly mounted tableaux vivants featuring, among others, Hay Petrie as a corpulent Tiberius Caesar ... and Laurence Olivier in fine voice as the grandiloquent balloonist Vincent Lunardi. However the film was not immediately released--appearing belatedly in 1940 in a much truncated form--running for only seventy-one minutes—and with many of its original sequences either missing or drastically curtailed—but with additional scenes added impress the extent of Britain's growing military airpower. During the wholesale dismantling of the original footage, no account was taken of Bliss's music, which was copped up along with the film stock" .... (Liner notes by David Wishart)
So keep in mind when viewing the film as it now survives that this is a very poor "remix" of something we will almost certainly never see, and that might have been very fine.
"CONQUEST OF THE AIR was planned as an epic chronicle of mankind's romance with flight from the early legend of Icarus to speedy aerial circumnavigations of the modern age. This history was to be retold as a series of lavishly mounted tableaux vivants featuring, among others, Hay Petrie as a corpulent Tiberius Caesar ... and Laurence Olivier in fine voice as the grandiloquent balloonist Vincent Lunardi. However the film was not immediately released--appearing belatedly in 1940 in a much truncated form--running for only seventy-one minutes—and with many of its original sequences either missing or drastically curtailed—but with additional scenes added impress the extent of Britain's growing military airpower. During the wholesale dismantling of the original footage, no account was taken of Bliss's music, which was copped up along with the film stock" .... (Liner notes by David Wishart)
So keep in mind when viewing the film as it now survives that this is a very poor "remix" of something we will almost certainly never see, and that might have been very fine.