Complex sentence: Jones hurried to re-fashion the score for orchestra in the limited time left, while the constant re-cutting of the film meant music cues sometimes had to be rewritten several times to keep-up with the new timings.
Split into simpler sentences: Jones hurried to re-write his score for orchestra in the limited time left. His efforts were handicapped by the constant re-cutting of the film, which meant his music cues sometimes had to be rewritten several times to fit new timings.