Clef: A clef is a symbol placed at the beginning of a staff that determines the pitch range of the notes on that staff.
Ledger Lines: Ledger lines are short horizontal lines added above or below the staff to extend its range for notes that fall outside the staff's normal range.
Accidentals: Accidentals are symbols used to alter the pitch of a note by raising or lowering it by a half step. Examples include sharps (#), flats (♭), and naturals (♮).