Complex sentence: The first movement needed some re-working because Barbirolli was not convinced it made sense in its original form, and the work was scheduled for the 1951 Cheltenhaam Festival where it caused a minor sensation.
Split into simpler sentences: The first movement needed some re-working because Barbirolli was not convinced it made sense in its original form. The work was scheduled for the 1951 Cheltenham Festival where it caused a minor sensation.