Transcript Introduction to Computer Music Synthesis

Computer Music Synthesis
MUET 495
Denny Lin
Copyright © 2011 by Denny Lin
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Objectives of this course
• Explore the history of computer music
• Learn sound synthesis techniques using
computer software
• Build a MIDI music synthesizer system
Copyright © 2011 by Denny Lin
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Definitions of Computer Music
• Computer music includes theory and application
of technologies in music:
– Sound Design and Synthesis
– Digital Signal Processing
– Acoustics
• Computer music is rooted in electronic music,
and early experiments in electronic instruments
• Recently, all music created with computing
technology is called “Computer Music”
Copyright © 2011 by Denny Lin
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Approaches to Computer Music
• Computer Generated Music
– Computer-generated scores for human players
– Composed and performed by computer
– Computer-Aided Algorithmic Composition
• Machine Improvisation
– Create improvisations based on existing musical
material, by using machine learning or pattern
matching algorithms
• Live Coding
– Interactive on-the-fly programming, integrating data
from real-time controllers and gestures
Copyright © 2011 by Denny Lin
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Music Synthesis
• Music Synthesis is a particular application of sound
synthesis
• Sound synthesis is the process of generating sound
from:
– Mechanical equipment: Pipe organs
– Electro-mechanical equipment: Telharmonium and Hammond
organs
– Analog electronic equipment: Moog and Buchla synthesizer
– Digital electronic equipment: All MIDI controlled, and computer
software based synthesizers
• Computer Music Synthesis is the software driven
approach to synthesizing sound for musical purposes
Copyright © 2011 by Denny Lin
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Popular Sound Synthesis
Techniques
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Additive: Combine (adding) many waveforms pitched to different
harmonics, each with different amplitude envelope, and inharmonic
artifacts
Wavetable: Restricted form of additive synthesis, where all partials or
overtones are harmonic
Subtractive: Remove harmonic content from sound using low-pass
filter(s)
Frequency Modulation: Alter or distort the (carrier) audio frequency of
an oscillator with the amplitude of another modulating audio signal
Granular: Cloud of layered sonic events, each 5-100ms long from
synthetic waveforms or samples, played at different speed, phase and
volume
Sampling: Multiple recordings (samples) of instruments are made for
each of its registers, and sound levels
Physical Modeling: Use the physical model of an instrument, and
mathematical equations to simulate its sound
Copyright © 2011 by Denny Lin
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Short Timeline of Music Synthesis
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1870s
– Gray’s Electric Telegraph for
Transmitting Musical Tones
– Edison’s Phonograph
1890s – 1900s
– Aeriol Piano (First substantially
complete player piano)
– Pianola
– Telharmonium or Dynamophone
1910s - 1920s
– Ondes Martenot
– Theremin
– Trautonium
1930s - 1940s
– Magnetophon and Stereo tape recorder
– Hammond organ invented
1950s – 1960s
– Scott’s Clavivox
– Schaeffer’s Concrete Music
– RCA Synthesizer (driven by punchedpaper tapes)
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1950s – 1960s (continued)
– ADSR Envelope specified
– Chowning discovers FM synthesis
– Voltage Controlled Oscillators
– First music synthesis software created:
MUSIC 1
– Moog Synthesizer
1970s – 1980s
– MiniMoog, Buchla Synthesizers
– IRCAM opens
– Yamaha DX-7
– MIDI born
1990s – 2000s
– Software-based synthesizers
– Interactive computer-assisted
performance
– MAX released
– Home-based production studios in
software
Copyright © 2011 by Denny Lin
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Note Names, MIDI Numbers, and
Frequencies
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12 Tone-Equal-Temperament Notes
Vs. Frequencies
Graph of Note Numbers vs. Frequency
(Note Number 58 is A=440)
25000
Frequency
20000
15000
10000
5000
0
1
4
7
10
13
16
19
22
25
28
31
34
37
40
43
46
49
52
55
58
61
64
67
70
73
76
79
82
85
88
91
94
97
100 103 106 109 112 115 118 121 124
(Not MIDI) Note Numbers
Calculated results
Data from book
Copyright © 2011 by Denny Lin
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Challenges
• Find an equation that describes the curve
of musical note frequencies
• Write a program that calculates the
frequency of each note in real-time,
without frequency lookup
• Program should play recorded notes from
file
• Are other frequencies less “valid” than the
12 tone-equal-temperament tuning?
Copyright © 2011 by Denny Lin
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A PureData MIDI Sequencer
Copyright © 2011 by Denny Lin
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References and PD Links
Sound Synthesis and Electronic Music references
1.
http://en.wikipedia.org/wiki/Sound_synthesis
2.
http://en.wikipedia.org/wiki/Electronic_music
3.
http://en.wikipedia.org/wiki/Computer_music
4.
http://music.calarts.edu/~eric/
5.
http://pcm.sapp.org/timeline/
6.
http://www.phys.unsw.edu.au/jw/notes.html
MUET495 Textbooks:
1.
http://aspress.co.uk/ds/pdf/pd_intro.pdf
2.
http://en.flossmanuals.net/PureData/_booki/pure-data/pure-data.pdf
PD Documentation
1.
http://www.crca.ucsd.edu/~msp/Pd_documentation/index.htm
PD Tutorials
1.
http://www.pd-tutorial.com/english/index.html
2.
http://obiwannabe.co.uk/tutorials/html/tutorials_main.html
Copyright © 2011 by Denny Lin
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