Standing Waves and Strings: teacher key

Music and Instruments, grade 10 edition, written for 10th grade. Why open and closed tubes sound different, how a violin's inside shapes its voice, how instruments are sorted, and a bone that scientists still argue about.

Read the book. Print this page for the key.

Questions and answers

1. What kind of harmonics does a tube closed at one end have?
   • Only even multiples
   • Only odd multiples (answer)
   • No harmonics
2. What does the soundpost do in a violin?
   • It holds the bow
   • It tunes the strings
   • It connects the belly to the stiffer back (answer)
3. What does a talking drum do to change pitch?
   • The drummer squeezes the cords (answer)
   • The drummer plugs it in
   • The drummer blows into it
4. What fifth class did Sachs add in 1940?
   • Pianophones
   • Voicephones
   • Electrophones (answer)
5. What happens to a theremin's volume as a hand nears the horizontal loop antenna?
   • It gets higher
   • It gets lower (answer)
   • It stops
6. How many languages are the Voyager greetings in?
   • 55 (answer)
   • 5
   • 550

Words

• fundamental: lowest frequency
• harmonics: overtone family
• organology: instrument science
• electrophones: electric instruments
• cochlea: ear's snail shell
• theremin: hands-free instrument