Teen Spirit


Even before I finished my previous experiment I already knew the next one was going to be about sound. I wanted to do music visualization in the browser.

And one more time the result of the experiment is quite different from the initial idea. But I quite like that, it is one of nice things of experimentation, the direction can change any time something interesting appears in the process.

I started by playing around with Web Audio API and looking for references. I found this cool project called Decorated Playlists, a website ‘dedicated to the close relationship between music & design.’ One of the playlists – Run For Cover – had some nice visuals with bold lines coming towards the viewer with a strong perspective. I imagined how those lines could react to music and replicated them in code. On these initial tests I was using a song from that playlist called Espiritu Adolescente, by Mandrágora Tango Orchestra – which is a cool tango version of Nirvana’s Smells Like Teen Spirit. It was looking good, but nothing special. I tried a few variations here and there and eventually dropped the idea.


Time for a new experiment. And a new song. I am a big fan of rock, so I started looking for the next tune in my own music library. I chose God Hates A Coward, by Tomahawk. I love this song. There is an awesome live version on YouTube where we can see Mike Patton barking the lyrics behind a mask.

That mask could be interesting to use in a visualization, so I started googling images of masks.
This one grabbed my attention. It seems to be a drawing based on this photo, but instead of the text on the cylinder, there are just lines. Once again I imagined how those lines could look when reacting to music.


So I went to code to try to replicate that cylinder. I tried a few geometries in three.js, but I realized I need more control of the vertices. It was one of those moments when my brain just wouldn’t shut down. I remember figuring out how to do it on the street walking back from lunch. The solution was to divide the bars into segments and then stretch the vertices only until the limit of the segment. i.e. if a bar has 10 segments and the value it needs to represent is 0.96, it is not like the entire bar is scaled down to 0.96, with this system the first 9 segments are assuming values of 0.1 and only the last segment is scaled down to 0.06. Then those segments can be distributed around a circle and the shape is preserved for any value.

The more I saw those bars reacting to music in 3D, the further away I got from the idea of the mask. The circular bars had something on their own and I couldn’t stop playing with them. Eventually I dropped the idea of the mask. And dropped also the song I was using. In my tests I found that the bars were reacting much better to the Nirvana tango I was using earlier. At this point the two experiments merged.

I feel stupid
And contagious
Here we are now
Entertain us

I didn’t know exactly what to do with all those shapes. All I knew was that some of them were looking pretty cool at certain camera angles and light positions, so I started to create some scenes with my favourite settings. I have to say it was a constant battle in my head between using pre-defined scenes or make everything dynamic. Some people might just start clicking and close the experiment because it doesn’t react. But I wanted to make something tailored for that song. Something like Robert Hodgin’s Solar. Everything is generated by code and runs real-time in the browser, but it could also be a video.


The creation of these scenes is what took most of the time. There was a lot of experimentation and a lot of stuff didn’t make it to the final version. Together with the sound reactive bars, I can say there were two other major accomplishments: one was to finally get my head around quaternions to be able to tween the camera smoothly – I should write another post about that I wrote on stackoverflow instead – and the other was to add the words ‘hello’ and ‘how low’ in a way that would fit well with the visuals.

I plan to explore these two topics a bit more in the future. And I definitely want to do more music visualization. Hopefully next time with some rock n’ roll!

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