Transcript Lecture 21 - UCF Physics

Lecture 22
One Last Musical Instrument
November 12, 2004
When did all of this start?
 Our ability to make sounds was probably
initially a way of warning others of danger.
 It was also a way of calling to other members of
the “clan .. pack ..”.
 It is not clear what came first … speech or
music.

They probably developed together.
 The first musical instrument was therefore
probably (who really knows??) the almost
human voice.
Verbal communication is probably the
“glue” that allowed civilization to
develop.
 Again – warnings
 Calls to draw members of the
group together
 Calls to the opposite sex
 Music ---> seduction??

“smooth” sounds
 Pleasant voice fluctuations leads
to “song”
A Quick History
 We don’t know much about the good old days of BC.
 In 367 AD, The Council of Laodicia banned all
congregational singing so choir singing became
necessary.

Music was believed to be pretty “holy” and not to be trusted
in the hands of the common folk.
 In 600 AD, Pope Gregory set up schools to train choirs.
The Gregorian Chant probably evolved from this.

Strong, versatile MALE voices were called for in this kind of
singing.
More Quick History
 13th Century – Composers were also
singers and music became the domain
of “high pitched” male singers.


Timbre specifics unknown.
Perhaps nasal?
 Chaucer:
 “Ful
week she soong the service dyvyne,
 Entuned

in hir nose full semely”
Or who knows???
Voice Registers
 15th century


Bass, Tenor, Alto, Descant (very high)
Falsetto singing became popular
 Renaissance


Women’s voices became popular because
“only certain kinds of women” sang in
public!
Sopranos became the rage.
 especially
on HBO!
Next step was the castrato.
More Castrato – Positions Available,
Somewhat difficult start but great $$$
potential.
It
Hurts!
The popularity of the motion
picture "Farinelli" (1994)
contributed tremendously to
the current surge of interest
for works originally written for
castrati. Of course, a cruel and
inhuman custom of castration
has since long gone, the best
we can hope for is a vocal
approximation performed by
sopranists, countertenors,
mezzo-sopranos or female
contraltos
With the passage of time
 More and more music for voice has been
and is being written with an increasing
complexity from generation to generation
 Singing somewhat followed the way that
musical instruments developed.
 OK .. enough history … all of this and
more is in the textbook (Johnston).
Vocal Range – Fundamental Pitch
♩ 329 Hz ♩392 Hz
♩ 82 Hz ♩98 Hz
♩523 Hz
♩131 Hz
♩587 Hz
♩147 Hz
♩880 Hz ♩1175 Hz
♩165 Hz ♩196 Hz
Tenor
Soprano
Mezzo- G – D
♂:
C2 – C5 ♀:
6
Soprano 3
Baritone
E – A5
Bass G2 – G4
Contralto 3
E2 – E4
D3 – D5
Remember open and closed
tube resonances??
BOTH ends open
Open
End
Closed End
Open Tubes
 Standing waves are
just like a string!
 Ends are PRESSURE
NODES
 Resonant Frequencies
are multiples of the
fundamental.
 These are the ONLY
strong tones that can
be played on this tube
The Human Open Pipe(s)
Open End of Tube
Vocal Chords Do it All!
Open
Balloon Thing
Spectral analysis of a female voice. Note that the
peaks occur at multiples of about 270 Hz (C♯).
How do they do that?????
Vocal Range – Fundamental Pitch
♩ 329 Hz ♩392 Hz
♩ 82 Hz ♩98 Hz
♩523 Hz
♩131 Hz
♩587 Hz
♩147 Hz
♩880 Hz ♩1175 Hz
♩165 Hz ♩196 Hz
Tenor
Soprano
Mezzo- G – D
C2 – C5
6
Soprano 3
Baritone
E – A5
Bass G2 – G4
Contralto 3
E2 – E4
D3 – D5
♂:
♀:
Changing Frequency
Higher Frequencies FALSETTO
Sound “shape” from vocal
chords
Fourier
 Lived 1768-1830
 Mathematician
 Fourier’s Theorem

Joseph Fourier
ANY periodic function
can be recreated as the
SUM of oscillations at
the frequencies
represented by the
harmonic series … f1,
f2……. f425 ….
Using Fourier’s Idea
=
An example . consider this
shape:
Nine Terms
Your vocal tract
 Has many different possible lengths.
 You adjust them with your muscles, your
tongue, and lots of other things.
 Your lungs literally make you a
“windbag” for the purpose of making
sounds.
 The vocal chords produce a periodic
pressure wave that enters the vocal
tract.
One Example
The component waves whose frequencies resonate with the
length of the “tube” are the ones that come out the loudest.
Articulated Speech
Suppose this
is how we make
a particular
vowel sound
FORMANT
Some Formant Combinations
Some Specific Formant
Frequencies
We adjust the tube length using
some feedback from the ear.
Because we sing WORDS, we
need speech articulation
While the singing voices look
like this.
So ………
 The human voice is the ONLY instrument
that can entertain itself!
 It also is a beautiful sound because it is
ours and we grew up with it.
 And because it has lots of harmonic
content.
 We can adjust our fundamental tones to
exactly match other voices … the chorus
is born!
Next … the impact
of electricity and
magnetism on
music and its
performance