Hi, Peggy. I gather, by the seven month spacing in your posts, that you are still struggling with the design of this quilt for your daughter? You obviously don't want to merely 'settle' on something and that is to be admired.
I think possibly the reason you are not 'taken' by many of the designs you've seen is because they are predominantly composed (no pun intended) of straight lines and angles. Music flows, bends and soars and a quilt created with at least some curves would do the same.
This design, for instance, is greatly enhanced by the swirling notes along the bottom.
http://www.theozmaterialgirls.com/me...ze-p-1001.html
If you are comfortable working with curves, either pieced or appliqué, consider including them in your design ideas. Curves can still have the formal feel you are looking for and can be either repetitive (i.e., rhythmic) or varied. Just something to think about.