David Løberg Code Groven.Max: School of Music Western Michigan University Kalamazoo, MI 49008 USA An Adaptive Tuning
[email protected] System for MIDI Pianos Groven.Max is a real-time program for mapping a renstemningsautomat, an electronic interface be- performance on a standard keyboard instrument to tween the manual and the pipes with a kind of arti- a nonstandard dynamic tuning system. It was origi- ficial intelligence that automatically adjusts the nally conceived for use with acoustic MIDI pianos, tuning dynamically during performance. This fea- but it is applicable to any tunable instrument that ture overcomes the historic limitation of the stan- accepts MIDI input. Written as a patch in the MIDI dard piano keyboard by allowing free modulation programming environment Max (available from while still preserving just-tuned intervals in www.cycling74.com), the adaptive tuning logic is all keys. modeled after a system developed by Norwegian Keyboard tunings are compromises arising from composer Eivind Groven as part of a series of just the intersection of multiple—sometimes oppos- intonation keyboard instruments begun in the ing—influences: acoustic ideals, harmonic flexibil- 1930s (Groven 1968). The patch was first used as ity, and physical constraints (to name but three). part of the Groven Piano, a digital network of Ya- Using a standard twelve-key piano keyboard, the maha Disklavier pianos, which premiered in Oslo, historical problem has been that any fixed tuning Norway, as part of the Groven Centennial in 2001 in just intonation (i.e., with acoustically pure tri- (see Figure 1). The present version of Groven.Max ads) will be limited to essentially one key.