Music Technology

  • ITA01 Music Technology

    • Course period: third quarter (autumn)
    • Course year: 1,2
    • Course type: elective
    • Credits: 2
    • Coordinator: Julián Villegas
    • Instructor(s): Julián Villegas (Michael Cohen).


    The purpose of this course is to study the fundamentals of audio signal processing and its application to music. Besides reviewing the underlying techniques, this course focuses in practical implementations of sound effects, so the course is intense in hands-on exercises, assignments, and projects mainly based on Matlab/Octave, C/C++, and Pure-data.


    • Students who approve this course are expected to understand the basic techniques employed in computer music, as well as the literature and terminology on this topic.
    • Students at the end of the term should be able to decide which of the presented techniques is best for creating a desired sound effect in music.
    • Upon completion of this course, students should be able to create their own sound effect chain.


    1. Introductions: Course overview, materials, examination, introduction to computer music technologies.
    2. Basic Filters: Parametric filters, FIR filters, Convolution, Equalizers, Shelving filters, Peak filters, Wah-wah filter, Phaser, Time-varying equalizers
    3. Delay: Basic delay structure, FIR comb filter, IIR comb filter, Universal comb filter, Fractional delay lines, delay-based audio effects, Vibrato, Flanger, chorus, slapback, echo, Multiband effects, Natural sounding comb filter.
    4. (continuation)
    5. Modulation: Ring modulator, Amplitude modulator, Single-side-band modulator, Frequency and phase modulator, Detectors, Averagers, Amplitude scalers, Vibrato, Stereo phaser, Rotary loudspeaker effect, SSB effects, Simple morphing: amplitude following, Modulation vocoder.
    6. (continuation)
    7. Nonlinear FXs: Dynamic range control, Limiter, Compressor and expander, Noise gate, De-esser, Infinite limiters, Musical distortion and saturation effects, Valve simulation, Overdrive, distortion and fuzz, Harmonic and subharmonic generation, Tape saturation, Exciters, Enhancers
    8. (continuation)
    9. Time-segment processing: Variable speed replay, Time stretching, Pitch shifting, Time shuffling and granulation
    10. Phase-vocoders: Basics, implementations, effects (time-frequency filters, dispersion, time stretching, pitch shifting, stable/transient components separation, mutating, robotization, whisperization, denoising)
    11. (continuation)
    12. Source-filter processing: ”Source-filter separation, Channel vocoder, Linear predictive coding (LPC), Cepstrum, Source-filter transformations, Vocoding or cross-synthesis, Formant changing, Spectral interpolation, Pitch shifting with formant preservation”
    13. (continuation)
    14. Time, Frequency warping : Algorithms for warping, Short-time warping and real-time implementation, Vocoder-based approximation of frequency warping, Time-varying frequency warping, Pitch-shifting inharmonic sounds, Inharmonizer, Vibrato, glissando, trill, etc.
    15. (continuation)


    • U. Zölzer, editor. DAFX – Digital Audio Effects. John Wiley & Sons, New York, NY, USA, 2nd edition, 2011.
    • Various materials prepared by the instructors

    Related courses which include important concepts relevant to the course

    This class does not have prerequisites, but it is recommended that students be familiarized with Pure-data programming paradigm, and general audio signal processing techniques. These are some classes that students are encouraged to take before this class:

    • ITC02 Introduction to Sound and Audio
    • ITA07 Advanced Signal Processing
    • ITA10 Spatial Hearing and Virtual 3D Sound

    Evaluation method

    Exercises and quizzes 40% Assignments 30% Final project 30%

    Referential sources

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