Designing the DrumKit

Our challenge was to design an educational product that would create new learning opportunities for fifth and sixth grade students and both excite and empower them in a new area. We were interested in exposing students to the intersections between sound, music, math, and physics, a topic which fascinates us and provides interesting ways to look at both art and science.

In order to explore the possibilities for educational products in this area, we built several experimental prototypes and brought them to a sixth-grade classroom for feedback.

A Laser Oscilloscope

Our first prototype explored the potential for sound visualization in an interactive system. We built a homemade oscilloscope that could project a waveform onto a wall, making an audio signal visible in real, physical space. Students could interact with the visualization itself by playing a synthesizer and observing the results—which might or might not be predictable.

The oscilloscope was based on a laser pointer directed towards a rotating reflector, which would cause the beam to scan back and forth horizontally. The reflected beam would bounce off of a second mirror coupled to the membrane of a subwoofer. Any audio signal sent to the subwoofer would cause the mirror and the reflected beam to vibrate vertically, resulting in both an audible sound and a visible waveform.

We wanted to know whether sixth-graders would find this compelling and whether it would spark curiosity about the science of sound. Small groups of students were presented with synthesizer software on a laptop and given a short amount of time to play with the device. We found that the complexity of the synthesizer limited students' ability to explore it in depth, but despite that challenge, they were interested in multiple aspects of the device: the sound waves themselves, the possibilities of the software, and the mechanical workings of the device. Their reactions prompted us to experiment further with musical devices, leading to a design we nicknamed the Eduitar.

The “Eduitar”

Our next prototype focused on the tangible aspects of music as a vehicle for learning. We took inspiration from stringed instruments, which naturally demonstrate the concepts of vibration, resonance, tension, length, and frequency, linking math and science with music in a familiar way. The Eduitar took advantage of this through affordances for scientific observation and measurement.

The Eduitar is a two-string guitar with “sliders” that can be placed under each string. The sliders allow users to change the length of the string and produce notes at different pitches. The soundboard has a ruler for measuring the length of the string (or string segments). In addition, the soundboard can be connected to a guitar tuner, which displays the frequency (in Hertz) and pitch (e.g. A, A#, B) of a given note. This combination would reveal the relationships between string length, frequency, and pitch: for example, when the string length is halved, its frequency doubles, and its pitch increases by an octave.

When we met with students, we were able to use the device to demonstrate the basic relationships. However, the students found the device itself boring compared to the oscilloscope. Although the device was a good strategy for learning and teaching, we realized that we would need to design something more “magical” and exciting in order to support a deeper learning experience.

Towards a Final Design

For our next project, we hoped to develop something that would, again, naturally encourage learning, but with much more flexibility than the Eduitar. We had several aims for the final design:

• The first two projects represented a potential for rich interaction though sight, sound, and touch, and we wanted to capture this richness.
• We wanted to find a novel, compelling approach that would motivate and excite students in a way that a more mundane object could not.
• We also wanted to design an educational product that would not contrain students with regard to what they could learn; instead, an ideal solution would open up possibilities for discovery in multiple domains and allow students to take their own path in learning.

On the educational level, we moved towards programming and away from sound itself as the focus of the product. However, we kept music as the basis for the design. Inspired by LilyPad Arduino as well as a variety of robotic instruments built in the past (e.g. LEMUR), we decided to develop a robotic drum set that would openly extend the Arduino platform. The solution would provide a flexible framework for both programming and musical rhythm, also leaving open the possibilities of learning about math or acoustics.

Our solution: DrumKit Arduino