How to add text to selected note (MS3.3)

var cursor = curScore.newCursor();
cursor.rewind(Cursor.SELECTION_START);
console.log('Segment:', cursor.segment)
console.log('Selection:', curScore.selection)
var text = newElement(Element.STAFF_TEXT);
text.text = 'test1';
cursor.add(text);

var selectedElementsArray = curScore.selection.elements;
if (selectedElementsArray.length > 0){
var elem = selectedElementsArray[0];
var root = elem.parent;
console.log(root.name, root.add);
var text = newElement(Element.STAFF_TEXT);
text.text = 'test1';      
root.add(text);
}