The Human Harp is a project led by artist Di Mainstone with hardware and software engineering by Becky Stewart and Adam Stark. The project draws inspiration from suspension bridges and explores how they can be transformed into musical instruments through augmentation with physical computing interfaces.

Our 3 hour NIME workshop was held at Goldsmiths and lead participants through the hardware and software central to the Human Harp - in particular the hardware string interface and the sound generation software. Participants were able to get hands-on experience programming and testing the Arduino-based hardware and then a guided tour through the software generating the audio.

Programme

The Human Harp is an open source project that is releasing all associated code and design files under creative commons and open source licenses. However, not all members of the NIME community may be comfortable with programming Arduinos and setting up bespoke physical interfaces. In this workshop, participants will be guided through how to install and test microcontroller code using the Arduino environment and then using the data stream generated by the Arduino to control audio playback.

The workshop introduced the Human Harp project framed within its artistic and technical objectives. The participants were able to physically interact with the different modules of the installation that generate audio before being led through the microcontroller code and audio software. By the end of the workshop, participants learned how to access open source software on Github and set up a Human Harp for their own development.

The workshop started with a talk from Di Mainstone about the creative inspiration for the piece and the history of the project. The current prototype of the physical computing interface will be demonstrated and then workshop attendees will be led through the technology.

By the end of the workshop, participants learned how to robustly develop hardware and software for live performance through the case study of the Human Harp. They gained hands-on experience programming and testing hardware built around the Arduino toolchain along with software frameworks, using tools common to open source communities such as Github.

Di Mainstone began her research by exploring the role of a bridge player with dancer Hollie Miller, who subsequently became Human Harp's original movician. The movician was a player of the Human Harp who controlled the sounds of the bridge via their body movement and interaction with the Human Harp's string like interface which connected to the bridge.

“We observed that the string mapped Hollie’s position via a physical line from its origin onto her body. We liked the physical aspect of the string as a sound tool (rather than motion tracking for example) as it allowed the movement of the user (or movician) to be plotted in a sculptural way, creating a visible trace between the performer and the bridge” Di Mainstone

Next, Di built a wearable holster around Hollie that would connect her body to the bridge via the Human Harp. This holster needed to be both rigid and flexible and they decided to work with leather.

“We knew the holster needed to be solid so that it would not pull away from the body and prevent the user (movician) from sensing the tension and pull of the harps strings that would be fixed to it. It also needed to have the capability to expand and contract like an armadillo or a piece of plate armour, and as such became a mechanism in its own right” Di Mainstone

Working with product designer, Lea Aubertin, the team devised a plug-like device that contained magnets to connect the retractable chords to the holster. The plug was created in Rhino, ensuring that it could be made using fab-lab tools (laser cutter) as part of the open-source concept.

“During the workshops at CIID we explored ways of clipping the strings to holsters on the body. We investigated karabiner clips, hooks and magnets. Of all the iterations, magnets felt the most fluid way to apply and reapply the strings to the body” DI MAINSTONE

Back in London, Di Mainstone spoke to professor Mark Plumbley at the Centre for Digital Music at Queen Mary University of London to secure support for the first version of the Human Harp...

“I thought it would be interesting if this bridge instrument used harp-like strings to control the harvested environmental sounds – mirroring the elegant cables of a suspension bridge” DI MAINSTONE

Di consulted Dave Meckin, a PHD student at the Media Arts and Technology group at QMUL. Dave and Di had used string in a similar way for a collaborative project called Whimsichord, so he had strong ideas on which sensors would be appropriate to measure the pull, length and twang of the string. Keen to make the harp as versatile as possible, Di envisaged something that was modular, bendy and magnetic, so that it could be set up at any location to take on the shapes of the urban environment.

“I saw this as an instrument for urban sound interventions. It should be assembled and pulled down swiftly and with ease. Because of this, it made sense to create segments that could clip together like a caterpillar, or stand-alone as single modules. Each module would be magnetic or clip-on so that it could attach to most metals and surfaces without damaging the integrity of the structure” DI MAINSTONE

Di connected with industrial designer David Blair-Ross, to investigate the housing and mechanical engineering of the bridge sound controller – which was now named the harp note. The pair decided that the module would be transparent so that the structure of the bridge was visible through each segment.

“This transparency suited the open-source nature of the project, making visible the mechanical and digital technology within. On a practical level, we wanted to make sure the module was weather proof and would also withstand being dropped, and so incorporated a rubber washer in the design” DI MAINSTONE

The team wanted to make sure that the design could be downloaded and reproduced by researchers and students using a laser cutter. David Blair Ross produced a 3d model of a module, and fabricated the first prototype.

“Before heading off to Copenhagen we met with our technical producers, Becky Stewart and Adam Stark to discuss how all of the digital elements would fit inside the harp casing. Each module needed to contain a spring, a spool, 8 meters of string, 2 kinds of sensor, an Arduino-mini and batteries.” DI MAINSTONE