Introduction to Electronic Music > A Glossary

Electronic music, put simply, is any music that makes use of sounds created by electronic means. In the early days of electronic music, around the beginning of the 20th century, this included the use of room-sized synthesizers that converted electronic currents to audible sound. The use of acoustic and electronic instruments together is called electro-acoustic music.

As electronic instruments became cheaper and more widely available, some have been widely incorporated into jazz: the Hammond B-3 Organ, the Fender Rhodes electronic piano, and the electric guitar. Some jazz musicians have made more extensive forays into electronic music, like some of Miles Davis music of the 1980's, including his 1989 album Aura, a collaboration with Danish trumpeter and composer Palle Mikkelborg.

Many other musicians have made their own contributions in this vein. Listing their contributions is beyond the scope of this article, but range from the use of a few electronic instruments to albums produced almost entirely by computers. Check out the following introductory glossary of terms related to electronic music.

Glossary of terms related to electronic music:

1. Basic Elements of Sound: This is a list of the basic elements of what makes sound different from another. Our ears hear sound as a result of contact with vibrating columns of air, and so all of these terms describe basic characteristics of these vibrations, and how we hear them. Electronic musical instruments manipulate these elements through either electronic or digital technology.
   • Volume or Amplitude: The loudness of a sound, or the energy level or intensity of the sound.
   • Pitch or Frequency: The speed of a vibration. What we call "high" or "low" sounds or pitches.
   • Timbre: The quality of sound. For instance, every instrument has its own character that we can distinguish even when all other variables are held constant. The difference in quality is a result of the combination of frequencies present in a sound, or the frequency content. A musical instrument produces a single pitch that is the loudest, but it is not the only frequency produced.
   • Rhythm or Duration: The length in time of a sound.
   • Spatialization: Where a sound comes from. Our ears can distinguish in three dimensions where a sound comes from in relationship to our heads by comparing the two, slightly different versions of the sound heard by our two ears.
2. Signal: A sound represented in the form of an electronic current, or its digital equivalent. Think of the current running from your ipod through the wires to the speakers or headphones as a good example of a signal. Once a sound is turned into an electronic or digital signal, it can be modified by any of the following synthesis techniques.
3. Synthesis: Synthesis is the collection of techniques used by electronic musicians to manipulate the basic elements of sound. It includes the use of these and other basic tools, each one of which might have originally been a big box with loads of circuitry, and now can be done with a computer.
• Oscillator: A module that generates a simple sound, generally a sine wave, or a sound with a single frequency. To create complex sounds, many oscillators can be used.
• Filter: A module that attenuates, or scales up or down the amplitude of various frequencies of a complex sound.
• Envelope Generator: A module that controls the amplitude of another signal through the use of a control signal, or another electronic current fed into the module. For instance, an envelope generator can be use to mimic the "attack" of an acoustic instrument, in which the volume of the sound ramps up from nothing to the sound we hear in a matter of a few milliseconds.
• Synthesizer: A synthesizer is a basically a system which can produce and manipulate signals and then send the synthesized signal to speakers. Keyboard synthesizers aren't the only kind of synthesizers, just the most common since the piano keyboard is familiar to many musicians. The Theremin is an example of a synthesizer that does not have a piano keyboard.

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