How does a String Make a Sound? When a string is made to vibrate by rubbing or plucking, it communicates a frequency to the surrounding air. When these vibrations reach the tympanum (eardrum), they are perceived as sound. Without a medium (air or water), sound cannot be propagated. Rubber Band Shoe Box Demonstration
What is Resonance When one object vibrating at the same natural frequency of a second object forces that second object into vibrational motion. The word resonance comes from Latin and means to "resound" - to sound out together with a loud sound. Resonance only occurs when the first object is vibrating at the natural frequency of the second object. Tuning Fork Demo
The Overtone Series Fundamental Tone First Harmonic- One Octave Second Harmonic-One Octave + A Fifth Third Harmonic-Two Octaves Fourth Harmonic-Two Octaves + A Third Fifth Harmonic- Two Octaves + Fifth Sixth Harmonic – Two Octaves + Minor7th Seventh Harmonic-Three Octaves If the finger is placed at a whole fraction of the length of the string, the vibration produces a note in harmony with the fundamental note. This principle was discovered by Pythagoras already two thousand years ago.
Sympathetic Vibrations Pythagoras discovered that if one string vibrates with twice the frequency of an identical string, we hear the higher frequency as one octave higher in pitch than the lower frequency The vibrating systems on most musical instruments are made up of two or more vibrating systems working together to produce sounds loud enough to be heard by the human ear. Examples of instruments with two or more vibrating systems include the membranes of leather stretched across the tensioning loop of a drumhead, the strings and the sounding board of a piano. Other examples are the strings and the body of a guitar or violin, or the reed and air column of the air column of the clarinet. Demo On Piano
How Does a String Change Pitch? Length Thickness Tension