Light the TIGER, position it on the desired instrument (Bass, Guitar, Ukulele, Violin, Chromatic). My 9 year old son is used in guitar mode, grip the head of the instrument, scratching one rope, the closest note appears, the string number also 1 to 6, to match the note with the plucked string giving the Tiger will light green. A breeze. Reminder: E = M = corde1, B = Si = corde2, G = Sol corde3 = D = D = corde4, A = = corde5, E = M = severe corde6.