Charm, for solo viola and computer-controlled electric guitar, is one of a series of pieces titled The Little Melody Book (Melodiebuchlein). The Little Melody Book is not so much a composition as a compositional process, the output of which may be interpreted and scored for acoustic instruments or performed electronically. The instrumental versions of The Little Melody Book use a microcomputer and associated electronics to perform pattern matching (in the pitch and time domains between the instrumental part and templates stored in the computer's memory. Some of these templates are predefined, some are generated during the course of the performance. The computer responds to matches between instrument and template by playing electro-mechanical instruments.

In Charm, the computer uses pitch information from the viola to drive a customized electric guitar. Electrical relays control a set of hammers which travel over the guitar's fretboard. The hammers lightly strike the strings, producing harmonics and 'hammer-ons' In addition to driving the hammer relays, the computer controls amplitude and timbral modulation of the guitar. Ideally, deepening on the size of the hall, the viola is un-amplified to provide contrast between its sound and the guitar's. Special thanks to Evan Staetler for technical perspectives. -M. T.

MARK TRAYLE was born and raised on the West Coast. He attended the University of Oregon (B.A. 1977) and Mills College (M.A. 1982), studying composition with Robert Ashley, David Behrman and David Rosenboom. In the Fall of 1983 he co-produced the Axiom Music Series, a month-long festival featuring composers and performers form the San Francisco Bay Area. He is currently on the Board of Directors of UBU incorporated, a non-profit organization producing new music events in the Bay Area.

Typed by Cheryl Vega 8-30-95