Sverm-Resonans – Installation at Ultima Contemporary Music Festival

I am happy to announce the opening of our new interactive art installation at the Ultima Contemporary Music Festival 2017: Sverm-resonans.

Time and place: Sep. 12, 2017 12:30 PM Sep. 14, 2017 3:30 PM, Sentralen

Conceptual information

The installation is as much haptic as audible.

An installation that gives you access to heightened sensations of stillness, sound and vibration.

Stand still. Listen. Locate the sound. Move. Stand still. Listen. Hear the tension. Feel your movements. Relax. Stand stiller. Listen deeper. Feel the boundary between the known and the unknown, the controllable and the uncontrollable. How does the body meet the sound? How does the sound meet the body? What do you hear?

Approach one of the guitars. Place yourself in front of it and connect to your standstill. Feel free to put your hands on the body of the instrument. Try closing your eyes. From there, allow yourself to open up to the sound-vibrations through the resting touch and listening. Stay as long as you like and follow the development of the sound, and your inner sensations, experience, images, and associations as the sound meets you. As opposed to a traditional instrument, these guitars are “played” by (you) trying to stand still. The living body interacts with an electronic sound system played through the acoustic instrument. In this way, Sverm-Resonans explores the meeting points between the tactile and the kinesthetic, the body and the mind, and between motion and sound.

Technical information

The technical setup of Sverm-Resonans is focused on the meeting point between digital and acoustic sound making. Each of the guitars is equipped with a Bela micro-computer, which produces electronic sound through an actuator placed on the back of the guitars. There are no external speakers, all the sound generation is coming the vibration of the acoustic guitar. Each of the guitars produce a slowly pulsing sound – based on an additive synthesis with a slight randomness on the sine tones – that breathes and gives life to the soundscape. The guitars are also equipped with an infrared sensor that detects the presence of a person standing in front of the guitar, and which inversely controls the amplitude of a pulsating noise signal. That is, the longer you stand still, the more sound you will get.

About the installation

Sverm-Resonans at Sentralen

Sverm-Resonans is a new sound installation by Alexander Refsum Jensenius, Kari Anne Vadstensvik Bjerkestrand, Victoria Johnson, Victor Gonzalez Sanchez, Agata Zelechowska, and Charles Martin.

The installation is the result of the ongoing art/science research projects Sverm, MICRO and AAAI, three projects which in different ways explore human micromotion and musical microsound. Supported by University of Oslo, Research Council of Norway, Arts Council Norway, The Fund for Performing Artists, The Audio and Visual Fund, and The Nordic Culture Fund.

Hi-speed guitar recording

I was in Hamburg last week, teaching at the International Summer Shool in Systematic Musicology (ISSSM). While there, I was able to test a newly acquired high-speed video camera (Phantom V711) at the Department of Musicology.

The beautiful building of the Department of Musicology in Hamburg
The beautiful building of the Department of Musicology in Hamburg
They have some really cool drawings in the ceiling at the entrance of the Department of Musicology in Hamburg.

Master student Niko Plath was friendly enough to set aside some time to set up the system and do a test recording. Niko has been doing some fascinating work on measuring the motion of individual piano strings using the high-speed camera. For this type of study a camera-based approach makes it possible to measure the vibrations of individual strings without having to attach anything to the string or to the board.

Niko Plath setting up the high-speed camera system.

While Niko has recorded the piano strings with a very high speed (500 KHz!) and low resolution(124 x 8 pixels), I was interested in seeing how the camera worked at the maximum resolution (1280 x 800 pixels). At this resolution, the maximum speed is 7 500 frames per second, and the maximum recording duration is 1.1 second.

Even though the recording is short, the processing and exporting of the file (21GB) takes quite some time. So I only had time to make one recording to try things out: a single strumming of all the (open) strings on a guitar, filming the vibrating strings over the sound board.

The setup used for the recording: guitar, two LED lamps and the high-speed camera.

This was just a quick test, so there are several minor problems with the recording: one being that the guitar was placed upside down, so that the lower strings are at the bottom in the recording. Also, I did not hit the upper string very well, so that one only resonates a little in the beginning and decays quickly. Still, there is nothing as beautiful as watching high-speed recordings in slow-motion. Here you can see a version of the recording being played back at 100 frames per second:

Of course, I was interested in creating a motiongram of the recording. Rather than making this using a regular average technique, I rather used a slit-scan approach, selecting a single pixel column in the middle of the soundhole on the guitar. This was done using a few Jamoma modules in Max, and the patch looked like this:

The Max patch used to generate the motiongram from the high-speed video recording.

The full motiongram is available here (TIFF 11 069 x 800 pixels), and below is a JPEG version in a more screen-friendly format. Even though the recording is only a little more than one second long, it is still possible to see the decay of the vibration of the strings, particularly the first strings (from above).

Motiongram of the entire high-speed guitar recording.

Below is a version showing only the beginning of the motiongram, and how the individual strings were strummed. Notice the difference in the “cut-off” of the shape of the wave of each of the strings.

The first 1000 frames of the recording, showing how the strings were strummed.

No new scientific insights here, but it is always fun to see periodic motion with the naked eye. It is a good reminder that auditory and visual phenomena (and the perception of them) are related. Thanks to Niko for helping out, and to his supervisor Rolf Bader for letting me try the system.

Virtual slide guitar

Jyri Pakarinen just presented a paper on the Virtual Slide Guitar (VSG) here at NIME in Genova.

They used a commercial 6DOF head tracking solution from Naturalpoint called TrackIR 4 Pro. The manufacturer promises:

Experience real time 3D view control in video games and simulations just by moving your head! The only true 6DOF head tracking system of its kind. TrackIR takes your PC gaming to astonishing new levels of realism and immersion!

The tracker is supposed to work at 120fps, and Jyri’s video demo was convincing, so it looks like an interesting and cheap mocap tool.