Slide your fingers along the neck of a guitar and you’ll feel ridges. These ridges divide the neck into distinct regions called frets. When the string is pressed, its vibrating length is determined by the nearest fret. Frets closest to the sound hole produce the highest notes. Frets farthest from the sound hole produce notes of the lowest pitch.
Things Required:
Paper cup
Kite string
Tape
Ruler
Two paper clips
Pushpin
Directions:
Use the pushpin to punch a small hole near the centre of the bottom of the cup. Cut a length of kite string about 2 feet long. Pass the string halfway through the cup hole. Tie the end of the string (on the inner cup side) to the paper clip.
Pull the opposite end of the string so that the paper clip may become pressed against the inside of the cup bottom. Use tape to secure the cup to one end of the ruler.
Bend the other paper clip into an “S” shape hook. Fasten this hook to the opposite end of the ruler. Use tape to secure.
Tie the free end of the string to the paper clip. The string should be tied so that it may be taut and be “plucked.”
Trim away any excess string. Pluck the string. Describe the sound. Press down on the string to force it to contact the ruler. Pluck the string again. What has happened to the sound? Try pressing down at different points along the string. How does the location of the “press” affect the sound?
This Is What Happens:
When the string was first plucked, it vibrated freely along its entire length. This produced the sound with the lowest pitch. When you pressed down on the string, you shortened the length of the vibrating section. This shorter length produced a higher pitch. By moving this “end point,” you varied the pitch of the plucked note.
