Select notes in the Score Editor
Before you can perform some edits to notes in the Score Editor, you need to select them.
Select a note
Do one of the following:
Click the note head.
Select multiple notes by Shift-clicking or by dragging around the notes to enclose them.
Select all notes
Choose Edit > Select All (or press Command-A).
All visible notes are selected.
Select all notes following the currently selected note
Choose Edit > Select All Following.
Select all following notes of the same pitch as the currently selected note
Choose Edit > Select All Following of Same Pitch.