Yamaha CS-10 Owner's Manual page 4

WHAT
IS
A SYNTHESIZER
Unlike other musical instruments, the synthesizer
has no
fixed
sound of
its
own.
Thus, before
playing
it,
it is
necessary
to
make
the sounds. But with
the synthe-
sizer
you
will
be
able to
make,
with
your
own
hands
and by
synthesizing sounds, a
new
type of sounds
that
can never be
made
by any
other muscial instrument.
THE THREE ELEMENTS
OF
SOUND
How
does
a synthesizer
make
sounds? Before ex-
plaining the arrangement of
the
synthesizer,
let
us
consider
what
kind
of
properties sound
has.
Sound
produced by
such muscial instruments
as
the
piano
and
guitar has
an
interval
and sound
level,
accord-
ing to the keyboard
or chord
used.
It is
possible to
change
the intervals
by
changing
the length of the
chord
for the portion
that
is
vibrating.
In this case,
the
chord's
number
of
vibrations per
second
also
changes.
The
chord
will vibrate
more
slowly, the lower the
interval
becomes.
In
this
way,
it is
possible to express
the difference
in intervals
by
the
number
of
vibrations
(frequencies).
Interval
Bass sounds
Treble sounds
wwwv
However, between
the
sounds of
a piano
and
a
guitar,
there
is
a difference in tone even
when
both
sounds
are
of
the
same
interval:
no one
will
mistake
the
tone of
the piano
from
that
of
a guitar.
This
is
because
there
is
a difference in the
way
the chords
vibrate (the vibration
wave
form),
due
to
the
difference
in
the arrangement
by which
the
sounds
are
made
to generate, and because of
the difference
in
the shape and
size
of
the musical instruments.
Tone
difference
Tone
difference
is
reflected
in
wave
form.
Furthermore, even
when
both
the
interval
and
tone
quality
are
the
same
there
is
a difference
in
sound,
as
when
the
same key of
the piano
is
hit in a forcible
manner and
a
gentle manner,
it
would be
easy to
o
discern the two sounds from each
other because of
the
magnitude (volume) of
the sound. This
is
because
a
difference
will
be
produced
in
the
size
and
amplitude
of the chord
vibrations,
due
to the intensity with
which
the
chord
has
been
struck.
In
this
way,
sounds produced by musical instruments
have such elements
as
intervals, tone
and volume,
whose
differences render the
sound
with
certain charac-
teristics.
These elements
are referred to
as '*the
three
elements of sound", which
may
be
also
considered
as
being the difference
in
the frequencies,
wave
forms and
amplitude.
CHANGES WITH TIME
IN
SOUNDS
However,
the elements
which
render sounds with
certain characteristics are not confined
to
these three.
Taking
the piano
for
example,
the
volume
will
reach
maximum
the
instant
the
key
is
hit,
then
will
decrease
gradually.
When
the finger
is
released
from
the
key-
board, the
sound
will
fade out. In the
case
of the organ,
the action
of
depressing the
keyboard
will
cause the
volume
to
rise
to a
certain level,
which
will
be
retained
for the
duration
the
key
is
depressed.
The sound
will die
away
when
the
fingeixis
released
from
the key.
Envelope Maximum
volume
^
Envelope
(Such
lines
do not
really
exist.)
K£r ON
K£r OFF
Further,
in
such muscial instruments
as
the
trumpet,
the
harmonic spectrum
changes together with
the
change
in
volume.
The
tone changes too, along with
the passage
of
time.
Thus, such sounds
as
those
of
musical instruments
undergo deUcate changes
from
the time the sound
is
generated to the time
it
fades
away. The
mode
in
which
sound changes with time
is
known
as
"envelope".
HARMONICS
What must we
do
in
order
to
produce
electrically
sounds
that
have
the three elements
of
sound,
that
is,
the
intervals,
tone and volume,
and which vary with
time (has
an
envelope). Before going
into
the matter,
let
us
view
sound
again
from
a different angle.
As
regards the vibration wave forms by which
the
tone
is
determined,
it
is
known
that
any
given
wave
form can be measured by
using the sine
wave
as a
measure.
In
other words, aU
wave forms
can be
analyzed
into
a large
number
of
sine
waves. For
ex-
ample,
let
us overlap, over
a single sine
wave,
wave
forms having an
integral
multiple
number
of
vibrations.
c
o