Thus far in this unit, applications of sound wave principles have been made towards a discussion of beats , musical intervals , concert hall acoustics , the distinctions between noise and music , and sound production by musical instruments . In Lesson 5, the focus will be upon the application of mathematical relationships and standing wave concepts to musical instruments. Each natural frequency of the object is associated with one of the many standing wave patterns by which that object could vibrate. The natural frequencies of a musical instruments are sometimes referred to as the harmonics of the instrument. This is known as resonance - when one object vibrating at the same natural frequency of a second object forces that second object into vibrational motion.
Resonance is a common cause of sound production in musical instruments.
The tuning fork was the object which forced the air inside of the resonance tube into resonance. As the tines of the tuning fork vibrated at their own natural frequency, they created sound waves which impinged upon the opening of the resonance tube. These impinging sound waves produced by the tuning fork forced air inside of the resonance tube to vibrate at the same frequency. Yet, in the absence of resonance, the sound of these vibrations is not loud enough to discern. Resonance only occurs when the first object is vibrating at the natural frequency of the second object.