Composition, A Putting Together
So far in this on-going series of articles on music production, we have learned about the roles and goals professionals play in music production, about digital audio workstations, the studio of as an instrument, and microphone basics. In this installment of this series of posts on music production, we be introduced to musical sound, sound waves, and synthesis, as well as some examples of early musical synthesizers.
What Is Sound?
In physics, Sound is a vibration propagates as a longitudinal wave (or pressure wave) through a medium such as a gas, liquid, or solid (the air).
In physiology and psychology, sound is the reception of these waves by the ear and perception of them by the brain.
For practical purposes, when any object vibrates, it causes movement in the air particles. These particles bump into the particles close to them, which makes them vibrate too causing them to bump into more air particles. This movement, called sound waves, keeps going until they run out of energy. Even inaudible sounds can effect us. This is why you can feel bass sounds.
Sounds can be audible or inaudible to us, meaning within or outside of the human hearing range which is 20 Hz to 20,000 Hz. Sounds under 20 Hz are infrasonic and sounds over 20,000 HZ are ultrasonic. The average person can hear sounds down to about 0 dB about that of rustling leaves. Some people with very exceptionally good hearing can hear sounds down to -15 dB. If a sound reaches 85 dB or stronger, it may permanently damage to your hearing, especially after prolonged exposure. The amount of time you listen to a sound affects how much damage it will cause.
The word "synthesis" comes from the Greek word, synthesis, meaning a "composition, a putting together." In electronic music, synthesis is the process of creating sounds using synthesizers. A synthesizer (or synth) is an instrument that creates sounds via electronic signals and amplifies them with loudspeakers. Many, but not all, have musical keyboard like a piano. Others control devices include ribbon controllers, trackpads, patch cables, dials and knobs, etc. Synthesizers are unique when compared to conventional musical instruments, as their capabilities encompass sounds far beyond the range and versatility of conventional musical instruments.
An assortment of synthesizers
What Is a Sound Wave?
As mentioned above, sound waves are longitudinal waves that travel through a medium, like air or water. When we think about sound from a musical perspective, we often consider about how loud it is (dynamics) and what musical pitches we hear (notes). From the perspective of science dynamics are expressed through a wave's amplitude and is measured in decibels. Pitch is expressed as the wave's frequency or repetitions over time and is measured in Hertz. One Hertz means one vibration per second. The primary forms of musical sound waves are sine waves, square waves, triangle waves, and sawtooth waves.
Sine - A sine wave is the simplest of all waveforms and contains only a single fundamental frequency and no harmonics or overtones.
Square - The square wave is more complex than a sine wave as it contains additional odd harmonic content. As the name suggests, the envelope of a square wave looks square. When viewed on a waveform graph, it can be seen that the amplitude instantly changes from its minimum to maximum value - there is no smooth transition as seen in the sine wave.
Triangle - The triangle wave is comparable to the square wave in that it contains a fundamental sound plus odd harmonics. The power of each harmonic in the triangle wave is twice as low as their counterparts in the square wave. Thus, the power of the harmonics in the triangle wave is reduced twice as fast as in the square wave.
Sawtooth – The sawtooth wave contains both odd and even harmonics and is said to be the richest in terms of timbre when compared to the four common wave shapes.
What Is Noise?
You may associate the word "noise" with sounds to which you do not enjoy listening. However, in music, noise is various unpitched and indeterminate sounds. Noise plays a part in the timbre of many musical sounds, such as the consonants in the human voice or the sounds of unpitched percussion instruments. In physics, noise is actually considered indistinguishable from musical sound, as both are vibrations through a medium. The difference is psychological and arises when our brains receive and perceive the sound as musical or non-musical. In the graphic above to see various types of noise visualized.
White – All frequencies are same pitch and volume.
Pink – Pink noise is a sound used to mask unwanted noises in your environment. It emphasizes lower frequencies than white noise. It has been found to be emotionally soothing and help sleep.
Brownian (Brown)/Red – Even more emphasis on lower frequencies. Brown does not refer to color rather to Brownian motion, random motion of particles suspended in a medium.
Blue – Higher emphasis on higher frequencies.
Many people find these types of noise pleasant and even believe that listening to them helps them feel calmer. This is why people may choose to use a white noise machine to improve sleep or listen to ambient music that may contain elements of these types of noise. Psychological research does not support that certain types of noises do encourage sleep. According to the Sleep Foundation, "Studies suggest a white noise machine can reduce sleep onset for [hospital] patients, or the time it takes to fall asleep, by nearly 40% compared to patients who don’t use these devices."
Types of Synthesis
The most common forms of synthesis are subtractive, additive, and frequency modulation or FM synthesis. Other methods include granular synthesis and sample-based synthesis. In all forms of synthesis, the musician or engineer seeks to create a sound that they feel has the musical timbre, a tone color or quality of a musical sound, that is appropriate for their compositional or performance needs.
Specific timbres of specific sounds are related to the shape of the sound waves that the sound source creates. Timbres are often synthesized by using oscillators and noise generators. (An oscillator creates an electronic circuit that produces a periodic, oscillating electronic signal, which is often a sine wave or a square wave.) When playing a synthesizer, sounds are made by turning these electrical oscillators on and off. For example, when you press a key down, the sound turns on electronically and when you release it, it switches off.
Subtractive synthesis is the most common synthesis method. Standard subtractive synthesizerss only require a few components to create a wide range of timbres. A subtractive synthesizer will usually have multiple oscillators that produce multiple wave shapes (square, triangle, and sawtooth) as well as noise generators. A filter is then used to remove some of the frequencies of the harmonics to sculpt the sound the musician desires. The minimoog (see below) is an example of a subtractive synthesizer. When you "synthesize" the sound of a rainstorm by blowing air through your teeth, you are, in a sense, using subtractive synthesis.
Additive synthesis dates back to the early 20th century tone wheel organs. (See the Hammond Organ below). It consists to combining sound waves (sine waves) together to create richer sounds. In additive synthesis, you are building your desired timbre one harmonic at a time. Other types of additive synthesis include wavetable synthesis and physical modeling synthesis which are meant to create timbres more similar to those of natural instruments.
Frequency modulation (FM) synthesis uses one signal called a modulator to effect the frequency (pitch) of another signal called a “carrier.” The Yamaha DX-7 (see below) creates sounds with FM synthesis.
Other types of synthesis include granular synthesis, which creates more complex sound out of small samples of just portions of complex sounds called "grains" and sample-based synthesis, which creates new synthesized sounds out of recorded sounds.
In they video below, watch French composer Eliane Radigue (b. January 24, 1932)) demonstrate how she builds sounds with a synthesizer.
Examples of Early Synthesizers
Telharmonium (the Dynamophone) was an early electrical organ, developed by Thaddeus Cahill circa 1896 and patented in 1897. The electrical signal from the Telharmonium was transmitted over wires; it was heard on the receiving end by means of "horn" speakers.
The Hammond organ is an electric organ invented by Laurens Hammond and John M. Hanert and first manufactured in 1935. Various models have been produced, most of which use sliding drawbars to vary sounds.
German engineer, Harald Bode, was a pioneer in the development of electronic music instruments and created the first modular synthesizer and sound processor from 1959 to 1961 while at Wurlitzer. A modular synthesizer is an electronic music instrument composed of separate modules each of which served different functions. These modules can be connected together with patch cables or switches that create a sound, called a patch.
The RCA (Radio Corporation of America) Mark I was an analog synthesizer using punched tapes, brushes, electric relays built in 1951 that was desgiend by Herbert Belar (March 5, 1901 – December 7, 1997) and Harry Olson (December 28, 1901 – April 1, 1982). The RCA Mark II Sound Synthesizer (affectionately known as "Victor") was the first programmable electronic synthesizer. It was also designed by Belar and Olson at RCA and was installed at Columbia University in New York in 1957.
The. Mark II was built of a full room's worth of interconnected sound synthesis components. Composer Vladimir Ussachevsky (November 3, 1911 in Hailar, China – January 2, 1990) in New York, New York)and engineer Peter Mauzey (b. 1930) contributed to its design. The Mark II gave the user more flexibility and had twice the tone oscillators of the Mark I. Much of the music of composer Milton Babbitt (May 10, 1916 – January 29, 2011) was written on and for the Mark II.
While earlier electronic instruments, like the Telharmonium or theremin were manually operated, the RCA featured a music sequencer, that the user could program to play patterns or pre-selected sequences, which proved revolutionary in the era of Tape Music. The automated binary sequencer used a paper tape reader like the reels of a player piano. Listen to the Mark II in the video above.