Lately I've been listening a lot to Kate Bush's album Aerial - beautiful, wonderful stuff. The album cover is interesting too - the 'islands' that are reflected in the water are actually the amplitude envelope of a recording of some birds singing. This idea of 'looking at sound' in different ways has been something I've really enjoyed exploring over the last several years. To help visualize the harmonics in a piece of music, I wrote a program a while back that analyses the frequency content of a sound waveform and creates a spectrogram (spectrum over time) of it, colour coding the intensity levels of each frequency. I think I've found the bird song shown on the cover - it's 2:25 from the start of the song 'Aerial'. Here's what its spectrogram looks like: The parallel contour lines that are stacked one on top of each other are the harmonics of the bird song. (A synthesizer's been added to the recording, which has changed the amplit
...neurobiology, molecular biology, nanotech, signal processing...