How Sounds are Formed by a Synthesizer

Basic Terminology

Oscillator (the sound generator)

• The primary source of synthetic sound
• Able to produce different wave forms
• Mostly commonly: saw/sine/triangle/square/pulse/noise
• Each wave form has a distinct 'tone color' or timbre

Image from Wikipedia

In 'additive synthesis', waveforms are added together to create a sound

Image from Wikipedia

In 'subtractive synthesis', waveforms are edited through filtration

Image from Wikipedia


Image from Wikipedia

Filter

• Essentially a frequency-dependent amplifier
• A sound frequency range may be set (a 'pass band')
• Only sound above the range amplified   => high-pass filter
• Only sound below the range amplified   => low-pass filter 
• If there is no such range                     => all-pass filter
• Leaves only a reduced portion of the sound

Envelope

• Allows fashioning of sounds
• e.g. Gradual onset/gradual decline
• 4 main parts to an envelope
• Attack/Decay/Sustain/Release (ADSR)

Early synthesizers used 'analogue' techniques, whereas contemporary synthesizers tend to use 'digital' techniques

Increasingly, though, both technological principles are applied in free-standing synthesizer software or 'Soft Synths'

Analogue synthesis

• Electronic signals are continuous
• More inherent noise

Digital synthesis

• Electronic signals are sent at one of two levels
• Information is quantized

Patch cords

• Allow for combining of waveforms from different generators and allow a sound 'patch' to be extended and sequentially modified

US Coinage: Penny, Nickel, Dime, Quarter

Penny

• 1 cent

Nickel          

• 5 cents

Dime          

• 10 cents

Quarter      

• 25 cents

About the Head Gasket in a Car Engine

The usual internal combustion engine is a water-cooled four-stroke petrol design. It uses three circuits of working fluids:

1. Combustible air/fuel mixture
2. Water based coolant, usually with glycol admixed
3. Motor oil for lubrication

These are all vital, but must never be allowed to intermix.

Apart from sealing the cylinder, the head gasket also seals water and oil conduits between the head and block. 

Any connectivity between them will cause engine failure, or significant problems like 

• Burning oil (smoke from the exhaust)
• Blue exhaust smoke may be indicative of oil burning
• White exhaust smoke is an indicator of coolant burning

from wikipedia

Of Striped Mens' Shirts & Fashion Terminology

For vertical stripes, the following terms seem to be the most appropriate

• Butchers' stripe = wide
• Bengal stripe = narrow

Apparently, Jermyn Street in London was famous for its butchers' stripe shirts, commonly worn by professionals in the banking district

Patching with Analogue Synthesiser

From Wikipedia

A synthesizer patch is a sound setting.

Modular synthesizers used cables ("patch cords") to connect the different sound modules together.


Since these machines had no memory to save settings, musicians wrote down the locations of the patch cables and knob positions on a "patch sheet" (which usually showed a diagram of the synthesizer).


Ever since, an overall sound setting for any type of synthesizer has been known as a patch.

New York / New England / Islands ...

New York = a US state in New England
Capital = Albany
Largest City = New York City; population around 8 million

Long Island: captures 2 NYC boroughs - Queens; Brooklyn

Manhattan
- a borough of NYC - the most densely populated

Rhode Island = a US state in New England

New England = a cluster of 6 US states in North-Eastern corner:
- Maine; New Hampshire; Vermont: Massachusetts; Rhode Island; Connecticut