Groven's first efforts at building a variable-pitch keyboard instrument were actually with the piano. After much experimentation, Groven concluded that he would be unable to build a viable piano mechanism, and therefore he turned to the organ instead. The existing 36-tone pipe organ (in Oslo, Norway) needs to be either repaired, refurbished, or entirely rebuilt. The current automatic pitch selection device is almost 35 years old and does not always function properly and is not really suitable for public performance. Without a viable 36-tone keyboard instrument, a significant part of Groven's life's work would remain unheard and his centennial commemoration in 2001 would be incomplete. As such, plans are underway for the construction of an acoustic piano modeled after his 36-tone pipe organ. Like the organ, this 'Groven' piano would incorporate an automatic pitch selection device to allow real-time changes of tuning during performance. This feature would expand the pitch palette of the piano, allowing for more subtle nuances of pitch akin to that experienced by a string quartet or an acappella vocal ensemble. The goal is therefore to have the Groven piano system operational for participation in concerts and recordings of Groven's works as part of the centennial celebration in 2001.

        The general design of the Groven piano system would consist of three basic units similar to the overall design of his organ: 1) an input device (the keyboard manual), 2) a pitch selector, and 3) an output device (e.g., organ pipes, or in this case a set of three player pianos). More specifically, each component of the Groven piano system would be comprised of the following:

        1) Input device: piano keyboard
The input keyboard would be a full-length (88-key) piano keyboard from which the performer would play. The input keyboard would not produce its own sound, but would have a MIDI output to connect to a computer. For the sake of the pianist, the ideal input keyboard would be a regular, mechanical piano mechanism. This could be achieved by retrofitting an acoustic piano with player piano system such as the "PDS-128 Plus" by PianoDisc. The "PDS-128 Plus" provides a mechanical silencer bar that when rotated into place (by the flick of a lever), will prevent the hammers from striking the strings on the piano, yet allow MIDI data to be output. This silencing does not effect the touch of the keyboard mechanism itself and can be turned off to allow the piano to operate normally. The Yamaha Disklavier and Baldwin Concertmaster are likewise acoustic pianos with MIDI capability. It is of course also possible to use either a digital piano or a synthesizer as the input keyboard, many of which simulate the touch of a mechanical keyboard.

        2) Pitch processor: computer program
The input keyboard would send out a MIDI signal which would be fed into a computer. A computer program simulating Groven's electronic pitch selector would determine the appropriate pitches required and output this information via MIDI. One might compare the program to a spell-checker used with word-processors. Computer programs which simulate aspects of Groven's system have already been written by Jørn K. Arvidsen (1982), Lars Frandsen (1995), Knut-Einar Skaarberg (1995), suggesting that this is a feasible goal. A program for the Groven Pianio is currently being written in collaboration with Prof. James E. Steck of Wichita State University. Unlike Groven's hard-wired device, the computer program would be easily transportable to allow the Groven piano system to be installed at different locations. Another advantage of the computer program is that it would be possible to experiment with other kinds of pitch selection criteria than those originally employed by Groven.

        3) Output device: acoustic MIDI player pianos
The sound-producing component would consist of three separate acoustic MIDI player pianos, each tuned one comma (20 cents) higher than the previous one, following Groven's tuning system. (The pianos can, of course, be tuned to according to other systems as well.) The three pianos combined would result in 36 pitches (strings) per octave, matching the 36 pipes per octaves used in the original organ. Let us say, for example, that the pianist plays a C minor chord on the input piano. Of the three different tunings available for the pitches C, Eb, and G, the computer program may determine that, in order to produce a purely tuned chord, C and G should be routed to player-piano 1 and the Eb to player-piano 2. All three of these pitches would still sound simultaneously as if played on a single piano. Except for the physical tuning of the piano strings, these player pianos would require no special customization. An added feature of using MIDI player-pianos is that performances could be saved on disk or CD-ROM and replayed live exactly like the original performance.

        While the use of synthesizers is a less complicated and more portable solution than acoustic pianos, it is aesthetically less desirable for live performance. Especially in the case of traditional classical repertoire, the use of an electronic and/or amplified timbre would detract from the performance and would prevent a fair comparison of the tuning system itself against standard equal-tempered tuning. For ensemble pieces, singers and instrumentalists would prefer to perform with an acoustic instrument, rather than an electronic one. Similarly, most pianists prefer the physical touch, weighting, and control of a mechanical piano keyboard. The purpose of this project is not to create a new electronic instrument to substitute for the piano, but rather to expand the pitch resources of the latter. The fact is that other instrumentalists and singers already use more than 12 distinct pitches. The question Groven attempted to explore was what musical possibilities would exist if pianos could as well.