Jeff Snyder's instruments:
MEAPbook / counterharmonium - developed between May 2007-present. The MEAPbook is a USB control surface that includes 44 touch sensors on a flat surface. It is housed in a thin wood case (about 5/8" thick) and sends continuous data for each sensor describing the current amount of surface area covered on the sensor. This equates roughly to finger pressure on the surface, since the finger flattens out upon firmer pressure. The "concert" version of the MEAPbook is a two-panel version with 88 sensors, a hinge and a clasp, placed on top of a wooden resonator body (known as the MEAPbook pulpit). The concert MEAPbook is also known as the "counterharmonium". Like the countervielles, the counterharmonium produces an electronic sound signal which is amplified by the custom 4-channel power amp and send back into its resonating body, so that the sound emanates from the instrument itself, and is colored by the resonator shape and materials. The top-plate of the counterharmonium is made of Sitka spruce, and the sides, bottom and back are high-quality birch plywood.
more images of the MEAPbook and counterharmonium
Countervielles - developed from December2006-January 2008. Sixty-four wooden buttons are arranged to operate like four strings with 16 "frets" each. Currently, the treble countervielle is tuned in fifths, like a violin, and the tenor version is tuned in fourths, like a bass. The instruments are designed to play in an extended just intonation system, in which all of the pitches are tuned to be related to a "base pitch" by whole number ratios. One rotary switch selects the base pitch, in effect altering all of the notes on the instrument slightly. The other rotary switch transposes all of the pitches up or down an octave, extending the instruments registral range. Currently, these instruments send "control voltages" to a modular analog synthesizer - one precise 16-bit voltage for pitch, and four voltages that correspond to the right-hand controls (which are capacitive touch-sensors like the MEAPbook). The sound of that synthesizer is then run into a custom 4-channel portable amplifier, and the amplifier drives large magnetic transducers screwed into the top-plate of the Countervielles. Those f-holes aren't just for looks! The wooden top-plate resonates with the sound the electronic instrument produces, and the tone color is affected by the shape of the instrument and the materials used in its construction, just like an acoustic instrument.