I think it is a gorgeous quilt. Very modern looking. I would mabe go ahead with the piano key but
put in a small black border.....then put a border of piano keys maybe instead of using all of the colors I would alternate between black and color ...so every other strip should be black ..and then put another black border to encase it all in....so you will just have blocks of colors around the edge of the quilt...will keep the modern look. I hhope that makes sense.