Charles Ives once declared that it wasn't composers' fault they were limited to ten-fingered pianists. Disregarding those limitations, American composer Conlon Nancarrow wrote an extensive series of studies for player piano whose rhythmic complexities are beyond any human performer: they have a breathtaking mathematical complexity yet don't sound like abstraction for its own sake. Nancarrow began his musical life as a jazz trumpeter, and many of the studies use jazz, blues, or boogie-woogie bass lines (though some other line that strays from the jazz style is always weaving around). Others start out as contrapuntal exercises and grow ever more complex, often signing off with a series of rattling glissandi. Though the studies are beyond the reach of a single performer, two pianists stand a chance. In recent years people have been transcribing these hair-raising works for piano four hands or for chamber ensembles. The Amy Williams-Helena Bugallo piano duo, which stands at the front of the line, will perform some of these works, including Study no. 9 (Bugallo's transcription) and parts of Study no. 3 (Bugallo and Williams's transcription). The rest of the program is given over to Japanese piano music performed by Rei Hotoda, who chose a wide-ranging group of pieces, from the pensive and introverted works of Toru Takemitsu to bolder ones by Toshio Hosokawa and Jun Kouda. The program will be played in the Fazioli piano showroom, putting the Fazioli sound on display. Tuesday 12, 7:30 PM, Pianoforte Chicago, Fine Arts Building, 410 S. Michigan, suite 825, 312-291-0000, $10.