I must not be understanding this pattern,I do see the pinwheels but why worry with them?I would strip set the checkerboard block (one light one color)using 5 strips and(turn each 1/4 turn befor I sewed the hst )on point and do a half square triangle( one light and one dark) on all 4 sides you can see they are set with the lights and darks arranged to form the pinwheels, then add a 3 or so inch strip with corner block then 2 colored piano keys with corner block and another strip with corner blocks would this not work? I would have 20 blocks. Maybe I would have a mess but...