Sync - Music
Music timing does not match on-screen coincidence.
Out of sync music negatively affects customer experience by providing a poor experience. It is typically attributed to improperly implemented music cues and is not usually representative of the creative intent.
On screen coincidence mismatches music by 1 frame.
On screen coincidence mismatches music by 2 frames or greater.
How to Prevent:
QC of M&E will help prevent out of sync music inherent to M&E from being present on all dubs derived from said M&E.
Monitor the placement of music on the timeline.
Fix sync on timeline and re-export.