Page  223 ï~~The Clavette: A Generalized Microtonal MIDI Keyboard Controller Harold Fortuin Institute of Sonology 6901 West 84th St., Apt. 219 Bloomington, MN 55438-1188 USA Tel: 1-612-941-7139/E-Mail: ABSTRACT: The Clavette, designed by Harold Fortuin, was built in 1994 thanks to support from the Institute of Sonology and STEIM in the Netherlands. It was developed to facilitate the creation and performance of live microtonal electroacoustic music in a variety of temperaments. The Clavette includes a membrane-covered 122-key keyboard, two three-dimensional foot pedals, and six footswitches. Typically, the keys are mapped to MIDI note numbers; the pedals to continuous controllers; and footswitches to program changes. Raw output is converted into MIDI data through the programmable STEIM SensorLab, which transmits it to a programmable synthesizer for audio output. The Clavette's 122 keys are heightened switches arranged in a hexagonal pattern in nine rows on a flat board roughly 21 by 29 cm. The distance between adjacent key centers in any direction is 2 cm. A transparent plastic envelope above the keys makes it easy to play two or three at once with one finger, and also enables key glissandos in a variety of shapes and directions. Paper templates customized for each tuning or key layout can be placed inside the envelope as a performance aid. The right and left foot pedals typically control MIDI velocity or continuous controller data for the corresponding half of the keyboard. The rotational axis can select which group of keys will receive the velocity level determined by the up-down axis. The roll pedal motions are typically used to control parameters such as vibrato, filter bandwidth, or glissando. The foot switches perform functions such as selecting another synthesizer patch, tuning, or set of key velocity groupings. The Clavette's basic performance techniques will be demonstrated, with an emphasis on its extensions of existing keyboard and pedal technique. It will be compared with other 20th Century microtonal keyboards such as Secor's Scalatron and Fokker's 31-tone organ. The presenter/inventor will perform several short pieces and excerpts, both transcriptions and original compositions, in various equal and just temperaments. These pieces will also present various mappings of foot pedal motion to MIDI continuous controller and pitch bend data. ICMC PROCEEDINGS 199523 223