London Queen Mary University of London

How Do We Design a Bridge Sound Controller?

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