Iterate VoiceEntries in a measure for a given staff, in beat order. Handles all null-guard boilerplate for the OSMD container/staff/voice traversal.
The SourceMeasure to traverse
Which staff to read (0-based global index)
Called for each VoiceEntry array (all voices at one beat position)
Iterate VoiceEntries in a measure for a given staff, in beat order. Handles all null-guard boilerplate for the OSMD container/staff/voice traversal.