I'm listening to the new recording by Jürgen Hocker of Conlon Nancarrow's Studies for Player Piano -- one through twelve on this CD. It's interesting music and this recording uses "two precisely synchronized original Ampico player pianos."
In small doses, this precise music can be exciting. For an entire CD, the lack of color is wearing. I'll keep listening but I look forward to someone's future rendition via computer software in the colorful manner of the Ensemble Modern orchestral arrangement.
Hocker has also recorded player piano versions of Ligeti's Etudes. Hearing this right after the Nancarrow makes for an interesting contrast -- not as rhythmically unusual, not so methodical, and less melodic, but even more of a fascinating blur. Humans also play this music? Amazing.