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Very briefly, the analog synthesizer is a device that is voltage controlled. This means that the components of a synthesizer operate by being 'driven' by voltages of various strengths. These voltages (and the changes represented by them) can be applied to many different parameters such as loudness, pitch, filtering, attack, etc.

Two different kinds of current may be used: DC (direct current which is a constant 'push' or 'pull') and AC (alternating current which alternates with positive and negative voltage--this is also the type of signal that drives the speakers of a stereo, producing the compressions and rarefactions). The synthesizer doesn't really produce sound--it produces voltages, alters them, and then those voltages are used to drive a speaker. If those patterns of voltages are very similar to something familiar to our ears, we would then conclude that it is creating a good imitation of a non-electric sound.

The oscillator is the heart of an analog synthesizer (see the glossary below). It produces an alternating current, which is then modified by some of the other components of a synthesizer. This oscillator is controlled by a DC voltage. If an oscillator is driven by x volts, it will produce a tone. If we increase the driving voltage, the pitch goes up. If we decrease it, the pitch produced will go down. The notes on the keyboard are discrete switches of that DC controlling voltage.

The big advantage of a synthesizer is that it can be voltage controlled on many parameters. That DC controlling voltage can be driven by an AC voltage, which will cause the pitch to go up and down, producing one of the most common synthesizer effects. That driving voltage can also be applied to other parameters such as loudness, tone color, space (in the case of a stereo signal), etc.

Extremely complicated and rich sounds can be made by controlling the control voltages. Larger (and generally the very early) studio synthesizers can be patched (wired) to have several controlling steps in the process. These are also very large in size. Smaller synthesizers can do only one or two steps of this, but have the advantage of portability.

Digital synthesizers produce sound with different algorithms, but many are designed to produce the same basic effects and manipulations made by an analog synthesizer. Some types of synths, known as wavestations, use waveform patterns created by things such as voices, woodwind instruments, sound effects, etc.

Um glossário de música eletrônica

AC (corrente alternada) [alternating current]
This refers to electrical current that changes direction (alternates). It is very similar to the oscillation found in air that creates sound: it becomes very important in an analog synthesizer.

Deals with information stored or transmitted on a sliding scale with an infinite number of values, as opposed to digital storage. Analog storage can capture the infinite gradations found in a set of values (for example, there are an infinite number of temperatures between 32F and 33F or and infinite number of temperatures 1:01 PM and 1:02 PM) The major problem with analog data storage is that the information is almost always compromised when the information is copied.

DC (corrente direta) [direct current]
Opposite of AC. In a synthesizer, this is often used to drive an oscillator to produce a wave at a certain speed, producing a certain pitch. Each key on a synthesizer will produce a different level of a DC, producing a different pitch for each.

This refers to information stored in discrete values or steps--there are a finite number of decimal places that can be expressed.

GERADOR DE ENVELOPE [envelope generator]
An envelope generator is a module on a synthesizer that acts as an amplitude gate over the time of a musical note. Although it does not affect the tone color of a sound, it is very important in the final effect. Most envelope generators have four controls. They are:

      the part of a sound that goes from zero amplitude to           
          its peak. 
      the part that drops from the peak to the sustain

      the part that remains at a constant volume. 
      the part that drops from the sustain level to zero

Removes parts of sounds or signals fed through it. There are three primary types:

   high pass filter 
      allows high frequencies to pass; filters out low. 
   low pass filter 
      allows low frequencies to pass; filters out high. 
   band pass filter 
      filters out frequencies within programmable ranges. 

Musical Instrument Digital Interface. It allows two way communication between a computer and a synthesizer, taking advantage of the computer's storage and editing capabilities.

A component that combines sounds or signals. It can be used to add effects such as echo, reverb, etc.

When one signal modulates another, they create a resulting signal that has characteristics of both.

   amplitude modulation (tremolo) 
        a rapid change in loudness. 
   frequency modulation (vibrato) 
        a rapid change in pitch. 
   spatial modulation (panning) 
        a rapid change in stereo placement. 

An oscillator is the heart of an analog synthesizer. It creates the basic electrical fluctuation (AC) that is used to drive a speaker and create sound. Early synthesizers used sine, square/pulse, or sawtooth oscillators to create their basic patterns. Later synthsizers use digitally stored complex waveforms of instruments to create their sounds.

Overdubbing is sometimes referred to as "sound-on-sound", or "multitracking". It is a recording process where a musician will play and/or sing along with a previously recorded material, adding additional voices or instruments to the final mix.

A boundary or key element that is part of a whole, such as the parameter of loudness, parameter of pitch, of duration, etc.

Similar to white noise (see below), except pink noise emphasizes the lower end of the audio spectrum.

Adjusts the strength of a signal. A volume control is a type of potentiometer.

A synthesizer sound that contains a fundamental and has overtones that can be varied by the user.

AMOSTRAGEM [sampling]
Sampling is the process of recording a particular air pattern (such as a voice, an instrumental sound, or perhaps even a whole section of music) and storing that particular waveform. A sampler will then play back copies of that original waveform (as opposed to playing back square, sine, sawtooth waveforms) and manipulate it--with things such as filtering, changing the speed of the periodic frequencies, merging it with another sound, etc.

A synthesizer sound that contains a fundamental and ALL overtones.

A synthesizer sound that contains a fundamental and NO overtones.

Where two ends of tape are joined.

A synthesizer sound that contains a fundamental and even numbered overtones only.

A programmable musical instrument. It creates a series of voltage patterns and manipulates them through filtering, mixing, modulation, etc. These voltages are then used to create sound. In a technical sense, a sampler is not a synthesizer.

TOM/ONDA TRIANGULAR[triangle waveform/tone]
A synthesizer sound that contains a fundamental and even numbered overtones only--at amplitudes that differ from a square waveform.

A sound containing all frequencies in the audio spectrum. There is no discernable order in white noise. With filtering, and the appropriate envelope, white noise can be used to effectively imitate many non-pitched percussion instruments, explosions, wind, etc.


I'm going to use a working definition for electronic music that is "any type of live or recorded music that (1) makes use of non-acoustic instruments; (2) directly depends on special effects and processes that are a part of the electrical recording and/or amplification medium; or (3) could not otherwise exist without the recording process." This definition purposely includes a huge body of music (such as mainstream popular music and quite a bit of "classical music") that would not fall under this category in most people's thinking or even most texts.

For example: no one will argue that music performed on a synthesizer is an example of the electronic medium, whether it is the music of Vivaldi or a series of bleeps, blops, and hisses that sound like low budget science fiction movie effects. However, keep in mind that while a composition may be non-electronic, the recording process may cause it to fall into that category. J.S. Bach composed a concerto for 2 violins and orchestra in the early 1700's. When the orchestra has been digitally recorded onto a compact disc, when it has been played back on a machine that uses a laser and computer technology, it really hasn't been changed in the process. However . . . when a Russian violinist recorded one solo part, rewound the tape and recorded the other solo part, then the recording has become dependent on the electronic process--a performance that would be impossible for one man to accomplish live (unless you know of a four handed violinist--Siamese twins don't count).

A couple of decades ago, there was major controversy surrounding the different categories of electronic music. Those producing musique concrete proudly proclaimed the fact that no electronic source sounds were being used in their recordings, and those that produced purely electronic sounds were equally as proud that their music sounded as rich as the musique concrete people. Digital sampling came along a few decades later and completely clouded the issue. Today, given the richness of the computer as entering into all aspects of music, from composition to notation, to sound production, to recording, the controversy has been left far behind. These categories are presented as historical data.

  1. PURELY SYNTHESIZED (not computer generated)
    1. New musical sound--no traditional musical organization.
    2. Using traditional musical harmonies, rhythms, etc.

Categories IA, II and III more or less grew up around national lines in the 1950's. Purely synthesized music was associated with Germany where the electronic music facilities were often connected with universities. As the name suggests, musique concrete was common in France, where not surprisingly, it grew up around recording studios and their special sound processing equipment. Being the typical melting pot, category III--the combination--was the style that grew up in the United States. These international distinctions have long since dissolved.

Category IV is also a type of combination, synthesizing elements of the very old and the very new. During any type of live performances, there is a lot of give and take between the performers and even the performers and the audience, allowing a certain amount of on-the-spot interpretation to take place. This element is what keeps musical performances alive and responsive to the performing atmosphere. Taped electronic tracks add a challenge to this, because the recorder is steady and unchanging. It truly is a challenge to the performers to strike a balance between the rigidity of the recording and the flexibility of any other performers in the ensemble. The flip side of the coin is that it loses the exact precision and total artistic control that the composer had intended. But--given that music has traditionally been a framework for a musician's interpretation, is this necessarily a problem?

These first four categories have traditionally been very dependent on "classical tape techniques"--in other words, the physical manipulation of magnetic tape, such as cutting parts out (editing) and splicing them back together in an unnatural sequence; playing sounds backwards; greatly amplifying sounds; changing the speed, etc. Sound isn't necessarily subject to much manipulation beyond reverberation, echo, or other realtime effects. The magnetic patterns on tape ARE. This lends to an incredibly diverse variety of things that can be done with sound.

Category V has been around for quite a while, but has been taking on some very exciting twists recently due to the plummeting prices of computer hardware. With the capability of MIDI, it is now possible for one person with the appropriate computers, synthesizers and computer software, with the technical knowledge and musical knowledge, and a LOT of patience to nearly duplicate the complexity of the orchestral ensemble. Will we soon be seeing a time when a part of the average musician's training will be the use of a computer? In some musical fields, that time is already here.

For practical purposes, the computer has already revolutionized much music with its sampling capability. Many legal battles have yet to be fought over the rights to sounds and who owns them.


The Roman Catholic church has been one of the most powerful influences on the music history of the Western World. During the Middle Ages when the ability to read and write became nearly extinct, the Catholic Church kept the tradition alive. This also applies to the tradition of notating (and preserving) music. Of the existing music of that era, there is an overwhelming percentage that is sacred.

There are several reasons for this--one, monks who had the task of copying music were obviously biased toward the preservation of sacred music. Two, there really was a huge amount of religious music composed. In that era, the human body and condition was looked upon as flawed, imperfect, only a transitional period preceding eternal life. One of the permissible delights was in the elaborate glorification of God through architecture, art, and-- music.

One of the drawing points for this glorification was the Mass. Very elaborate musical traditions grew around this ritual, which is woven around the central points of the Christian religion. Over nearly the next thousand years (bringing us to the present which includes rock and jazz settings), the Latin text of the Mass has served as a libretto for some of the most inspiring works ever written. Later compositions make use of the sacred text in a concert setting, making it become more or less a secular libretto. A composer will deal with the internal story, the internal dramas as he would any other text. At the same time--even though they were never meant to be performed in church, many of them were composed in an act of sincere faith, each one a personal and fervent dialogue between the composer and his beliefs.

In spite of the fact that the music is split among the many segments of the service, the framework of the Mass is where the first unifying concept of form was utilized. Composers began linking the sections of the ordinary (see below) together by using common musical elements. The "Missa Notre Dame" by Guillame de Machaut was a landmark of the Middle Ages, being the first setting of the Mass ordinary to be composed by the a single composer.

Textually, the Mass is divided into two parts: the Proper and the Ordinary (which is the focus of modern settings and be marked with an asterisk). The Proper of the Mass consists of texts that change from day to day, season to season. The five texts of the Ordinary are remain constant throughout the liturgical year.

    Alleluia (or Tract in certain seasons)
    Lord's Prayer
    Agnus Dei
    Post--Communion prayers
    Ite Missa Est

In many of the more famous modern musical settings, the Kyrie (Lord, have mercy) is generally a softer, pleading movement. Sometimes the music composed for the three lines of text is very somber. The repetition of these lines over and over (a compositional necessity) adds to this effect. It will often be in a simple A-B-A form.

The Gloria (Glory to God in the Highest) is considerably longer and much more joyful in tone. The "amen" at the end is often harmonized in a gigantic fugue.

The Credo (We Believe in One God--known to Protestants as the "Nicene Creed") is the longest of the texts. As it deals with the greatest drama in the Christian faith, the music here will have the most dramatic impact. The heart and soul of the movement (textually and musically) is the section, "ex Maria Virgine; et homo factus est. Crucifixius etiam pro nobis sub Pontio Pilato: passus, et sepultus est. Et resurrexit tertia die, secundum Scripturas." This last statement is where the composer will usually pull out all the stops and let the fireworks fly--respectfully of course. But after all, that is the central point of the religion. This movement often ends in a tremendous musical celebration and affirmation.

The Sanctus/Benedictus (Holy, holy, holy) is often a quiet, reverent section. The recurring praise "Hosanna in excelsis" is often a good place to create some compositional unity.

The final movement of the Ordinary is the Agnus Dei (Lamb of God). Depending on the frame of mind of the composer, settings will often range from grand and theatrical to quiet and almost prayerful. Many composers will use some of their Kyrie music to add a very large unifying element, and quite probably to link elements of the text together in a final summation of purpose--Lord, have mercy [and] grant us peace. . .

Many settings of the Mass have been written by composers such as Machaut, Palestrina, Haydn, Mozart, Leonard Bernstein, Dave Brubeck, and the Electric Prunes. Arguments as to the greatest setting of the text will usually come to a standstill between the one by J.S. Bach (who ironically was a Lutheran) and the second one by Beethoven, his "Missa Solemnis"--an incredibly powerful and moving statement written from his anguished world of total deafness.

The Requiem Mass--the mass of the dead--is also the text of some of the most stirring choral and orchestral compositions. Later concert settings of this text are much less consistent than those of the Mass text. Most concert Requiems consist of:

   Introit (Requiem Aeternam) 
   Sequence (Includes Dies Irae and Tuba Miram)                      
   Agnus Dei 
   Communion (Lux Aetera)
   Responsory (Libera Me)

There are many marvelous musical interpretations of this text. Owing to the subject at hand, none of them are conducive to a party atmosphere. Surprisingly, there's a wide variety in the treatment of this text--from profound sadness and mourning, to an affirmation of life, to a calm acceptance of death as an inevitability, to cries of anguish. Gabriel Faure's setting is quite sedate, even omitting the section pertaining to the last judgement. At the point where the text "Tuba, mirum spargens sonum" is sung in Hector Berlioz's requiem, four brass bands cut loose in what is quite possibly the loudest section in all of classical music. Giuseppi Verdi's Requiem ends with a hair-raising "Libera me, Domine, de morte aeterna, in die illa tremenda", using string tremolos to depict the licking of the eternal flames of hell.

Although the Requiem Mass is not used by the Roman Catholic church any more, modern composers still find the text useful. Benjamin Britten's "War Requiem" makes use of the standard Catholic text mixed with poetry written by a soldier who died in WW I, producing a stark depiction of the horrors of war. "Requiem for Unbelievers" by Roger Ames (given its first performance by the Montgomery County Masterworks Chorus in 1985) also uses parts of the Requiem text interspersed with modern poetry, but this time by a poet whose works chronicled her voyage through depression, unbelief, and eventually to suicide, producing a very soul-searching musical document.


The following is a list -- actually three lists -- of recordings that are not only a good introduction to the music of the cited eras, but will be relatively easy to listen to and understand. It was very hard to limit this list to only thirty. Some choices have been very arbitrary. Many of these have been used in various movies, commercials, etc. so you may already be somewhat familiar with a few. All of these are available on compact disc.