Cue notes

From MusiCAD

Cue-notes are small-sized notes that are used in one part to mention notes from another part (without playing them) within a score to make it easier to (re)start after a long pause. You can use the shortcut <ctrl-k> to turn an ordinary note into a cue-note and vice versa, or use the note properties menu.

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Although cue-notes may look the same as grace notes, they fulfill a completely different task.