"The  second album from Zebra on Piston Source, Numberika demonstrates Zebra's mastery of pxtone soundscapes. More than just ambience,  Numberika's tracks  conjure  images and  emotions  through  its  sounds. If you liked Door's 'Planetarium Sky,' you'll love 'Numberika.'"

http://pistonsource.iiichan.net/indexen.html

You can grab a zip of mp3s at the link above, as well as the source files which can be opened in Pxtone Collage.