We hear recordings all the time: movie and
television soundtracks, ads, radio shows,
podcasts, music, voice, sound effects.
Recordings are everywhere. But what is a
recording... and how is it made?
Recordings are sound documents. Sound
waves are converted into electrical signals.
These signals are stored on a recording
medium, like a cd, a sound file on a
computer, or vinyl record. Copies can be
listened to multiple times.
Sounds can be captured using a microphone
which uses a diaphragm to sense sound
pressure and convert them into electrical
Some instruments use a
pickup to capture the
vibrations of the
instrument and convert
them into electrical
Acoustic guitar with pickup
The electric guitar uses pickups. This signal
passes via a cord to an amplifier. The
amplifier is then mic'd and that signal goes
to the recording device.
Some instruments, like
instruments can be
plugged directly into
This is called Line In
as opposed to Mic In. Analog Modular Synthesizer
Recordings have been made on wax
cylinders, magnetic tape, vinyl records and
cassette tape. But today almost all
recordings are made on a DAW (digital
audio workstation) in the form of recording
software on a computer.
Analog recordings used mechanical means
to record sound. Sound waves might be
etched into vinyl so that a stylus could
translate them back into an electronic
signal to play through a sound system.
Turntable with vinyl record
Or the sound would be
stored on tape
coated with a
Tape heads would
then read the tape to
convert the magnetic
information back into
2 inch, 24 track tape machine
Since 1982, with the invention of the cd,
digital recording has almost completely
replaced analog recording. Sound waves
are digitized. The recordings can be
stored as files on computer systems and
played an infinite number of times with
no loss of quality.
Digital recording requires two conversions:
AD which converts Analog to Digital and
DA which converts Digital back to Analog.
Digital information is stored as 1's and 0's
and can't be heard until it is converted
back to sound waves. This process is
referred to as AD/DA conversion.
In the early days of recording music, all of the
musicians played at the same time. One
microphone would be used to pick up the
sound of the whole group. These were
Later, stereophonic sound (stereo) was
developed. Stereo used two recorded
signals to create the illusion of 3
dimensional space on a recording. It
made it possible for sound to appear to
come from the left or right, or anywhere in
between, in the stereo spectrum.
In 1955 multitrack recording was invented.
This made it possible to record audio tracks
at different times, or even in different
places. An engineer could effect single
instruments without effecting others.
To keep track of and control these many
tracks, a mixing desk was required. A
mixing desk would have a strip for each
channel of sound.
Typically, this strip would
have a fader to control
how loud the sound was. It
would have a Pan knob
that would control where
the sound was, left or right
in the stereo mix. It would
have an EQ (equalizer)
section that could control
the high and low
frequencies of the track.
There would be sends and returns that would
allow you to use special effects such as
reverb, echo, compression on the individual
You could also group the channels, take 2 or
more of them and send them to be
controlled by 1 or 2 faders. This came in
handy if you had many instruments on
different tracks, such as a horn section,
that you wanted to control all at once.
A modern DAW (Digital Audio Workstation)
mimics these older technologies to make
modern recordings. You can import or record
multiple tracks. Your mixer will control your
levels. Plugins will allow you to manipulate
the sounds with various effects.
Digital Audio Workstation (DAW)
MIDI (short for Musical Instrument Digital Interface) is a technical
standard that allows electronic musical instruments, computers
and other devices to connect and communicate with one another.
MIDI carries messages that specify notation, pitch and velocity,
control signals for parameters such as volume, vibrato, audio
panning, cues, and clock signals that set and synchronize tempo
between multiple devices.
Sampling is the act of taking a portion, or sample, of
one sound recording and reusing it as an instrument or
a sound recording in a different song or piece. Modern
computers make sampling much easier than historically
possible as portions of music can easily be cut, copied,
pasted and looped. Sampling is now used in many
genres of popular music.
There are 3 stages to making a recording:
tracking, mixing and mastering. Tracking is
the physical act of recording the
instruments. This is usually done in a
A studio will have
several rooms that
have been specially
treated to record in.
The control room will
be separate from this
room so that none of
the sounds that the
engineer might make
will interfere with the
recording. Often there
is a vocal booth, a
special room just for
singing or speaking.
A control room
Different people perform different jobs in the
recording environment. The artists, made
up of musicians, singers, performers are in
charge of knowing their material and
performing to the best of their abilities.
set up the
run all of the cables
to the various
sure that everything
one way to mic a drum kit
Producers are usually hired to oversee the
entire project. They have a vision of how
the recording should sound and they coach
the musicians to get the required results.
When all of the tracks are recorded, it is time
for mixing. Mixing is where each track is
manipulated so that it sounds good with the
other tracks all at the same time.
DAW used for mixing
Volume, compression, limiting, reverb,
flange, chorus, equalization etc. may be
applied to change the quality of the sound.
When listening to a good mix, you should
be able to hear every instrument clearly.
Once the tracks have been mixed, the tracks
are sequenced, that is, put in an order. Just
like a play, or a movie, the record should
have a beginning, a middle and an end that
Then the tracks are submitted for mastering.
The mastering engineer uses software and
equipment to make the different recordings
of the entire record sound unified and even,
none too loud or soft.
A mastering studio
The mastering engineer also decides how
long the spaces between songs should be.
When this process is over, a master
recording or file is made that all
subsequent copies will be made from.