The left column ((a), (b) and (c)) corresponds to a parametric study of the variation of the length of the shaft L_r whose each studied length corresponds to the note of the cristal. In these plots the rectangular mass has always the same length. The right column ((d), (e) and (f)) corresponds to a parametric study where the length of the rectangular mass L_m is proportional to the length of the shaft L_r; (a)–(d) variation of eigenfrequencies for each particular resonator pitched on the note of the cristal, the principal mode M is underline by the + marker, the mode of the rectangular mass D is underlined by the o marker. The dash-dotted lines correspond to the eigenfrequencies of the mode A, B and C, these eigenfrequencies are calculated by a specific FEM where the threaded shafts are considered rigid; (b)–(e) is the minimal applied force calculated by LSA for each note and each pole, the color respectively refers to the mode in (a) and (d); (c)–(e) is an illustration of the resonator corresponding to the minimum and maximum note for the parametric study.