- Anne Beetem Acker
Hybrid acoustic instrument and hardware audio controller developed at the Stanford University Center for Computer Research in Music and Acoustics in 2009 by Colin Raffel, Nick Kruge, Diane Douglas, Edgar Berdahl, and Wendy Ju. Modelled after a hammered dulcimer, the prototype consisted of a square bamboo frame with an array formed by two perpendicular planes of eight strings each, the planes being a few millimetres apart. This arrangement is equivalent to a ‘button matrix’ of 64 buttons, allowing the use of applications for button devices. On two adjacent sides of the frame, the steel strings (pressed by the fingers or struck with a mallet) pass over individual bi-layer bridges with piezoelectric transducers sandwiched between the layers, while on each of the other two sides the strings cross over a shared bridge to endpins. Each endpin is then electronically connected to a microcontroller that sends data to a computer for processing. When two strings touch, through finger pressure or a rapid pluck with fingers or a pick at the intersection, that point acts as a switch or button. Multiple connections can occur depending on how the finger or mallet presses on the array of strings. Each string having its own piezoelectric pickup allows for its individual amplification, computer processing, and mapping to output devices. The two layers of strings can be tuned variously; when the two planes are tuned identically, the effect of sympathetic vibration results. Other tunings result in different intervals being formed by each crossing. Unlike traditional audio hardware controllers that use buttons and knobs, the Lattice Harp provides a tactile experience like that of an acoustic instrument....