1 1 Physics 198 Final Exam-Solution December 16, 2008 The exam ...

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26. If we choose to tune C 4 to 260 Hz as the first note in a Pythagorean scale, what
would be the frequency of G 4 which is a 5’th higher? The fifth’s are perfect in
Pythagorean scale give a ratio of 3/2. Hence (3/2)*260 = 3*130 =
⇒ 390 Hz.
27. Which tuning/temperament (Pythagorean, mean, just, equal) exactly closes the
circle of 5’ths?
⇒ Equal Temperament
28. Briefly but clearly explain the advantage of multiple pickups on an electric
guitar.
⇒ The anti-nodes for different harmonics occur in different places, and the
anti-node locations also change as frets are used. If several pickups are
used, all harmonic strengths can be sampled and mixed electronically.
29. In lecture, Simon kindly demonstrated a “pedal” tone with his tuba; Nolan
(trombone) and Ross and Chad (trumpets) later played these in labs. Which is
the most accurate description.
a. A pedal tone is the highest peak in the harmonic series of brass
instruments, and is often beyond one’s hearing range in pitch.
b. ⇒ A pedal tone is the lowest note in the harmonic sequence for a
brass instrument. The instrument does not actually have a resonance
there, but, when the instrument is played, the lips can be stabilized at
this frequency by the higher harmonics that do exist in the horn.
c. A pedal tone is obtained by “popping” the mouthpiece giving a
frequency of about 800 Hz.
30. Briefly but clearly explain what Formant Tuning is and where it is used in
music.
⇒ It is possible to align one of the resonant frequencies one of the vocal
cavities (formants) with the frequency of the note being sung. This
can give the sound great power. This is useful at the top end of the
soprano range where the note frequency is above most vowel
formants. I believe that Tom also used it effectively in his
demonstration of “throat singing” in lecture and in lab as well. (The
first sentence is sufficient for full credit.)
End of Exam and End of Course!
Have a Great Winter Break!
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