1. GOOD MORNING!
 Today we will:
 graph the relationship between:
 string length and frequency
 string tension and frequency
 take a short online quiz
 watch a 5 minute video on mosquito tones
 write a short (but accurate and scientifically precise)
response describing how a guitar makes music
 Please do before the bell:
 get your lab book
 get 1 whiteboard/marker per table
 get a netbook (leave closed on your desk for now)

2. the
HOW DO GUITARS MAKE relationship
between string
MUSIC? length/tension
to pitch

3. WARM-UP
As string length _______, frequency
_______.

4. WARM-UP #2
As string tension _______, …

5. REVIEW: FREQUENCY AND HUMAN
HEARING
All sound is caused by vibration
As the number of vibrations increases…
frequency increases
pitch increases
Even though all vibrations make sound,
not all sounds can be heard by humans.

6. FREQUENCY AND HEARING
Humans generally can hear sounds with
frequencies between 20 Hz and 20,000 Hz
As a part of the aging process, humans begin to
lose their ability to hear at the upper end of the
frequency…crafty teenagers take advantage of
this by installing “mosquito tones” on their cell
phone to “secretly” get text notifications in class
But…youthfulness is often outdone by age and
treachery… 

7. NETBOOKS & TBIRDSCIENCE
Log on to tbirdscience.org
(be sure you are on our website and not our blog)
New Page:
Practice Quizzes
Be sure to put your first and last name and
your email address before starting the quiz
no email = noemail@gmail.com
5 questions, 10 minutes