Continuum Fingerboard

The Continuum Fingerboard or Haken Continuum is a music performance controller and synthesizer developed by Lippold Haken, a professor of Electrical and Computer Engineering at the University of Illinois, and sold by Haken Audio, located in Champaign, Illinois.

The Continuum Fingerboard was initially developed from 1983 to 1998 at the CERL Sound Group at the University of Illinois, to control sound-producing algorithms on the Platypus audio signal processor and the Kyma/Capybara workstation.

In 1999, the first Continuum Fingerboard was commercially sold. Until 2008, the Continuum Fingerboard provided IEEE-1394 (FireWire) connections to control a Kyma sound design workstation, as well as MIDI connections to control a MIDI synthesizer module. More recently, the Continuum Fingerboard generates audio directly in addition to providing MIDI connections for MIDI modules, software synthesizers, and Kyma (the IEEE-1394 connection that was present on earlier models has been removed). An external control voltage generator permits control of analog modular synthesizers.

The Continuum features a touch-sensitive neoprene playing surface measuring approximately 19 centimetres (7.5 in) high by either 137 centimetres (54 in) long for a full-size instrument, or 72 centimetres (28 in) long for a half-size instrument. The surface allows a pitch range of 9350 cents (about 7.79 octaves) for the full-size instrument, and 4610 cents (about 3.84 octaves) for the half-size instrument. The instrument has a response time of 0.33 ms.

Sensors under the playing surface respond to finger position and pressure in three dimensions and provide pitch resolution of one-tenth cent along the length of the scale (the X dimension), allowing essentially continuous pitch control for portamento effects and notes that are not in the chromatic scale, and allowing for the application of vibrato or pitch bend to a note. A software "rounding" feature enables pitch to be quantized to the notes of a traditional equal-tempered scale, just scale or other scale to facilitate in-tune performance, with the amount and duration of the "rounding" controllable in real time.

The Continuum also provides two additional parameters for the sound: it is able to transmit the finger pressure on the board as a MIDI value, as well as the finger's vertical position on the key. These parameters are independently programmable; a standard configuration is where position on the X-Axis (lengthwise) on the instrument corresponds to pitch, position on the Y-Axis (widthwise) corresponds to a timbre shift, and position on the Z-Axis (vertically) corresponds to a change in amplitude. The Continuum is capable of polyphonic performance, with up to 16 simultaneous voices.

Each recent revision has brought more features and sound diversity to the internal synthesizer in the Continuum Fingerboard. As such, the instrument can now be considered both a controller and a stand-alone instrument.

As of 2008, the Continuum Fingerboard has a new modular digital synthesizer built-in, specifically designed for the Continuum Fingerboard, called The EaganMatrix. The EaganMatrix uses a patching matrix to design synthesis algorithms. The patching matrix interconnects a variety of modules: oscillator, filter, delay, modulation, waveshaping, spectral manipulation, modal physical modeling, waveguide physical modeling, kinetic modeling, granulation, and shape generator. Each three-dimensional performance direction of the Continuum playing surface can influence each patch point in the matrix. By defining formulas and placing them at points in the patching matrix, the user creates relationships between the finger touching the Continuum playing surface and the flow of sound from patch sources to patch destinations. The EaganMatrix is named after the Canadian composer Edmund Eagan.