a melody moves by small intervals called steps or by Larger ones called leaps . a step is the interval between two adjacent tones in the do-re-mi scale from do to re , re to mi , etc . ) . any interval larger than a step is a eap do to mi , for example . besides moving up or down by step or leap , a melody may simply repeat the same note . a melody's range , or the distance between its lowest and highest tones , may be wide or narrow , melodies written for instruments tend to have a wider range than those for voices . and they often contain wide leaps and rapid notes that would be difficult to sing .