This has nothing to do with Portland, but it's tremendously cool. From Jason Freeman's Piano Etudes site:
"Inspired by the tradition of open-form musical scores, I composed
each of these four piano etudes as a collection of short musical
fragments with links to connect them. In performance, the pianist must
use those links to jump from fragment to fragment, creating her own
unique version of the composition.
The pianist, though, should not have all the
fun. So I also developed this web site, where you can create your own
version of each etude, download it as an audio file or a printable
score, and share it with others. In concert, pianists may make up their
own version of each etude, or they may select a version created by a
I created my own version of "Observing Squirrels" this morning.