I came across a fantastic performance of a Bach prelude played on Boomwhackers by Les Objets Volants.

https://www.youtube.com/watch?v=Y5seI0eJZCg

It is really incredible how they manage to coordinate the sticks and make it into a beautiful performance. Given my interest in the visual aspects of music performance, I reached for the Musical Gestures Toolbox to create some video visualisations.

I started with creating an average image of the video:

Average image of the video.

This image is not particularly interesting. The performers moved around quite a bit, so the average image mainly shows the stage. An alternative spatial summary is the creation of a keyframe history image of the video file. This is created by extracting the keyframes of the video (approximately 50 frames) and combining these into one image:

Keyframe history image.

The keyframe history image summarizes how the performers moved around on stage and explained the spatial distribution of activity over time. But to get more into the temporal distribution of motion, we need to look at a spatiotemporal visualization. This is where motiongrams are useful:

Motiongram of vertical motion (time from left to right)

Motiongram of horizontal motion (time from top to bottom)

If you click on the images above, you can zoom in to look at the visual beauty of the performance.