CREATING SOUND - LAB

OBJECTIVES:

1. How the major musical instruments work.

2. Applied uses of sound.

BACKGROUND:
What we hear from all musical instruments is produced by sound waves.  A sound wave is a form of a physical wave. A wave is a disturbance caused by the movement of energy from one place to another.  The ability to sense sound is not only essential for survival, but is also a source of pleasure. 

Instruments which produce sound have been around since the dawn of mankind.  The earliest instruments were various kinds of percussion producing instruments in the form of drums, which were struck by the hand or sticks.  String instruments and woodwinds came later. 

When a person listens to music he or she hears many different sound waves.  Waves that occur together may change each other by the process of interference.

The difference between pleasant musical sounds and noise results from interference.  You are able to hear a radio or "boom box" playing in the next room because waves are able to move around a barrier such as a wall or door because of diffraction.

The pitch or tone of an instrument results from the frequency at which the instrument vibrates.  Higher pitched instruments such as violins and flutes vibrate at higher frequencies.  Lower pitched instruments such as tubas or bass violins vibrate at lower frequencies. 

Students will use three major groups of instruments and a frequency meter to determine the number of waves per second produced by each group of instruments.

PROCEDURE:
Students will blow through flutes and use a frequency meter to determine the number of waves per second.  Using finger tips, students will strike the edge and middle of a bongo drum and again measure the wave frequency.  Students will pluck one violin string and measure the frequency.