I have basically the same criteria for new piano music that I have for new music (or music that’s new to me, at any rate) in any genre (I really try not to be pianocentric!). Some of my favorite new works reside at both extremes of the new complexity–minimalist continuum, and at many places in between and outside. A few of the most impressive works I encounter also seem to create their own genre, to lesser or greater degrees.
In larger-scale works, I like to see a compelling level of interest at both the local and global levels. Locally, this can mean dramatic gestures, ethereal textures, propulsive and funky rhythms, great sonorities and lines—actually, too long a list of musical parameters preceded by enticing adjectives to cite here. But I also really want the whole to be more than the sum of the parts.
As an improviser as well as a “legit” player (Is there a better term for a performer of completely notated scores than the idiotic “legit”?), I certainly am attracted to music that employs well-integrated improvisatory elements or sections. But I am equally bowled over by the best works that happen to contain highly specific notation and indications.
I’m loathe to be pragmatic with “art”, but I have to say that I’m always on the lookout for works that can be received on different levels—something that has both a compelling surface interest as well as depth. Any work that’s brilliant to begin with, which also happens to suggest or synthesize idioms of vernacular music, is an added bonus. All of this is all wrapped up with the mission of getting away from insularity, and building audiences for new music.
As for live performances themselves, programming considerations are certainly unavoidable. One involves building interesting and/or thematic programs, something I find very important. And length is certainly a factor. It’s always much easier to program a set of miniatures or etudes sooner rather than later, as opposed to 30-60 minute long sonatas. Great works in the latter category are somewhat frustrating, as there are usually far fewer opportunities for performances.
I also really appreciate works that use the resources of the instrument brilliantly. This doesn’t mean that I’m looking for kitchen sink pieces, by any means. The expressive compass can be very small, while still being captivating, and still using the piano with an insightful understanding of the instrument’s capabilities.