RHY.9:4.1 - Recover the contributions and their receivers
Take a short passage containing the difficulty, including its entry and continuation. Identify what must continue, what must be articulated, who produces each contribution, and who needs timing information from it. RHY.2 and RHY.3 supply these distinctions when they are unresolved.
For each consequential cue, ask what its receiver must learn: the next entry, a cycle position, an approaching change of pace, a release, or permission to recover at a later landmark. Retain an already shared convention or demonstrate the intended cue. The same head movement can otherwise be read as an accent, a tempo change or preparation for an entrance.
A solo performer may use an internal reference. A partner can use it only through some accessible consequence. Add an external cue only where that receiving need exists.