Technical data
CLANGOROUS
SOUNDS
So-called
clangorous
sounds
are
often
characterized
as
being
metallic
or
"bell-like."
A
characteristic
feature
of
a
bell
sound
is
the
presence
of
partials
that
are
not
harmonic.
That
is,
partials
that
do
not
stand
in
whole
number
relationships
to
each
other.
On
the
Multimoog,
when
the
FILTER
section
is
in
the
TONE
mode
it
is
possible
to
use the
FILTER
MOD
BY
OSC
B
switch
to
create
non-harmonics
that
give
the
impression
of
metallic
or
bell-like
sounds.
The
following
exercise
shows
how
to
produce
clangorous
sounds:
EXERCISE
5:
FILTER
MODULATION
BY
OSCILLATOR
B
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1.
Hold
the
lowest
key
on
the
keyboard
down.
2.
Switch
FILTER
MOD
BY
OSC
B
to
the
WEAK
position.
You
should
hear
a
repeating
pattern.
OSCILLATOR
B
is
now
modulating
(changing)
the
cutoff
frequency
of
the
FILTER
section,
rapidly
changing
the
pitch
produced
by
the
FILTER.
3.
Slowly
rotate
the
WIDE
FREQ
control
in
the
OSCILLATOR
B
section
to
increase
thespeec/
of
the
modulation.
At
some
point
your
ear
no
longer
hears
the
individual
repetitions,
but
perceives
the
rapid
modulation
as a
new
timbre.
4.
Play
the
keyboard.
Try
different
WIDE
FREQ
settings.
5.
The
sound
produced
depends
on
the
frequency
and
waveshape
produced
by
the
OSCILLATOR
B
section,
and
the
frequency
that
the
FILTER
section
is
producing.
Explore
these
clangorous
sounds
by
trying
various
settings
of
WAVESHAPE
(B),
WIDE
FREQ,
DOUBLING,
and
CUTOFF
controls.
(END
EXERCISE)
This
is
an
example
of
use
of
an
oscillator
as
a
controller.
Notice
that
we
are
not
listening
to
an
oscillator
as
a
sound
source,
since
the
OSCILLATORS
switch
is
to
OFF.
But
OSCILLATOR
B
control
settings
still
affect
the
sound,
because
that
oscillator
has
been
connected
to
the
control
input
of
the FILTER
section.
To
make
an
analogy,
your
fingers
don't
make
sound
when
you
play
the
violin,
but
they
control
the
sound.
When
you
create
vibrato
on
the
violin
you
are
modulating
the
frequency
of
the
sound.
A
very
wide
and
rapid
vibrato
on
the
violin—if
humanly
possible-
would
create
new
sound
textures
that
are
bell-like.
On
the
Multimoog
it
is
possible
for
the
OSCILLATOR
B
section
to
act
like
a
finger
on
the
string
to
modulate
the
pitch
produced
by
the
FILTER
section
very
rapidly.
WEAK
and
STRONG
positions
on
the
FILTER
MODE
switch
represent
the
relative
amount
of
frequency
modulation.
NON-PITCHED
SOUNDS
NOISE
SECTION
In
synthesizer
language,
"noise"
is
a
random
signal—a
rushing,
static-like
sound.
The
sound you
hear
between
channels
on
FM
radio
is
an
example
of
noise.
The
NOISE
section
of
the
Multimoog
provides
"pink
noise"
that
has
been
balanced
to
have
equal
energy
in
all
octaves.
So,
it
sounds
neither
too
high
and
hissy,
nor too
low
and
rumbling.
Noise
does
not
have
harmonics
like
the
waveshapes
produced
by
an
oscillator;
noise
may
be
thought
of
as
all
frequencies
occuring
randomly,
or
without
order.
The
following
exercise
shows
you
what
unmodified
noise
sounds
like
on
the
Multimoog:
34