it can be a very pure sound like for instance, ♪ ohhhhhhh, which is, in a timbre, is very pure, and ife start applying different things to it, for instance, we can change the timbre of the sound by just changing the way that we create the sound. ♪ ohhhhaaaahh. and in fact, what i was doing was actually just opening up the vowel sound to explore the harmonic make-up of that sound. [light, airy tune] we take instruments to be things that produce tones, but each one of those tones in an instrument is actually a huge complex of smaller tones which we usually do not hear. and many musical instruments take advantage of the overtone series in order to produce musically useful tones. the overtone series is really quite simple. behind every acoustically generated tone, there is a series of other tones which are happening simultaneously. (shapiro) musical timbres are made by combinations of overtones, and you can do with a synthesizer what's called additive synthesis. you can build many overtones together, piling them one on top of another different--two times, four times, eight times the freque