A graph representing musical sounds has a shape that repeats itself over and over again. Such graphs can be displayed on the screen of an oscilloscope when the electrical signal from a sound sensor is measured. Pythagoras found that notes played together on musical instruments were pleasing to the ear when the ratios of the string lengths were the ratios of whole numbers. Galileo introduced the concept of frequency. A sequence of notes of increasing frequency make up a musical scale.
Many different scales exist.
This activity has three parts. In the first part, the Science Workshop program generates output signals that are amplified by the Power Amplifier and played through a speaker. In the second part, the Sound Sensor measures sounds from a musical instrument such as a harmonica or recorder. In the third part, the sound sensor measures sounds from a human voice. The Science Workshop program monitors and displays the output signals sent to the Power Amplifier and the input signals measured by the Sound Sensor.