The orange piece of couching looks very visable. I think if you couched around the black key edges in black, they would show up more. You could poosibly write "Music" in flowing scrip up on the upper blanket to tie it all together?
You could try clipping out the keys but I don't know if you could get it cut without cutting the background. If the black is just one layer, you might be able to carefully cut close to the stitching line on both side and with a pair of tweezers or hemostats, pull out the few threads under the stitching. Good luck.