Sine waves are simple things and provide a nice entry point to learning audio signal processing. So far we've been able to discuss things like frequency and amplitude using nothing but individual sine wave oscillators.
But the thing is, a solitary sine wave is not very interesting to listen to. It's a blank slate, devoid of any color, character, or drama.
Things start to get much more interesting when we have multiple sine wave oscillators at our disposal. What we can do is combine them to produce more complex sound waves. This technique is called additive synthesis.
In the previous article we discussed how we can change the frequencies of sounds to alter their pitch. Now we're going to talk about stretching sound waves along another axis, to change their amplitudes. This affects their loudness.
In the first article we constructed sine wave oscillators that had one particular frequency: 440Hz, or the A4 standard note. In this article we'll see how we can vary the frequency and how this results in different audible pitches.
Learning Web Audio by Recreating The Works of Steve Reich and Brian Eno
Posted on by Tero Parviainen
Systems music is an idea that explores the following question: What if we could, instead of making music, design systems that generate music for us?
This idea has animated artists and composers for a long time and emerges in new forms whenever new technologies are adopted in music-making.
In the 1960s and 70s there was a particularly fruitful period. People like Steve Reich, Terry Riley, Pauline Oliveros, and Brian Eno designed systems that resulted in many landmark works of minimal and ambient music. They worked with the cutting edge technologies of the time: Magnetic tape recorders, loops, and delays.
With Web Audio we can do something Reich, Riley, Oliveros, and Eno could not do all those decades ago: They could only share some of the output of their systems by recording them. We can share the system itself. Thanks to the unique power of the web platform, all we need to do is send a URL.