Released in 1998 a 2 disc intended restoration of Superman the Movie Soundtrack as a 20th Anniversary release had to be re-recorded due to discovery that the Archive of the Superman Music only contained Superman II & III. Much effort was made to locate the music but to no avail, all that they had to work with was a set of copies of John Williams original composer sketches, “there are occasional slight differences in the music’s arrangements and orchestration. But for anyone familiar with the original recording, the new approach gives the feeling of listening to the score once again for the first time…” firstname.lastname@example.org Link
Read the internal booklet for the whole process which ended up being recorded by the Royal Scottish National Orchestra. Please note that there are no Lyric’s to the the Flying Sequence (can you read my mind?) in this release.