## Glossary

filter
a modifier module in the synthesis process which allows certain specified frequencies to pass through unaltered, and at the same time removes or attenuates other specified frequencies.
Go to Topic: Filters
filter modulation
change induced in the frequency of the cut-off frequency of a filter by means of a control signal from a time-variant controller.
Go to Topic: Time-variant Controllers
Fourier Analysis
a method of analysis that breaks complex waveforms into their component frequencies.
Go to Topic: Complex Periodic Waveforms
Fourier Synthesis
the building of a complex periodic waveform by combining sine waves of various frequencies, amplitudes and phases.
Go to Topic: Complex Periodic Waveforms
frequency
the rate at which one cycle of a waveform is completed; frequency is expressed in cycles per second, c.p.s., or Hertz, or Hz.
Go to Topic: Frequency
frequency modulation
change induced in the frequency of a signal by means of a control signal from a time-variant controller. Also called FM.
Go to Topic: Time-variant Controllers
fundamental frequency, fundamental
the frequency that has the same period as the waveform. The fundamental frequency will always be the lowest frequency in a waveform.
Go to Topic: Complex Periodic Waveforms
generator
a general classification of synthesis modules. A generator is a module that initially generates the sound material which will subsequently be modified. Examples include the oscillator, the noise generator, and the digital recording.
Go to Topic: Generators and Modifiers
harmonics
frequencies considered partials are whole-number multiples of the fundamental frequency, e.g., 200, 300, 400, 500, and 600 Hz are harmonics of the fundamental frequency 100 Hz. The fundamental is the first harmonic.
Go to Topic: Harmonics
harmonic series
the relationship between the fundamental frequency and the upper partial frequencies when the partials are whole number multiples of the fundamental frequency.
Go to Topic: Harmonics
harmonic spectrum, spectrum
describes the specific harmonic makeup and the specific amplitude of each harmonic frequency contained in a waveform. A spectrum may also be non-harmonic.
Go to Topic: Harmonics
Hertz , Hz
how frequency is expressed, the same as cycles per second.
Go to Topic: Frequency
high-pass filter
a modifier module in the synthesis process which permits frequencies higher than a specified frequency (fc) to pass and removes or attenuates lower frequencies.
Go to Topic: High-pass Filters
input
to send a signal into a synthesis module or other device. The signal may be an analog or digital audio signal, or may be MIDI data.