Wow! Thank you all for the wonderful responses and ideas! I've decided that I'm just going with a solid block on this one. The center of the log cabins are tomato red, so I'm using that same, red fabric for each corner. It's quick, easy and it looks really good. I'm definitely keeping everyone's ideas in my mind for my next piano key border that is coming up. I love this border, so I'm planning to use it often.
~ Cindy