I think that people are missing the fact that this quilt will be on a bed, so the visual impact of the borders is quite different than when you see it laid out on a flat surface. I really like the coral fabric, and I see nothing wrong with having it on only 3 sides, but I think it would look nicer to have a narrow strip of it on top too. I think piano keys would be too busy. You want the center of the quilt to be the attraction, so the plain border will look fine, especially when the quilt is on a bed. And it is a charming quilt - you did a great job of adding to the size.