I used 3 boxes French White Cake, and used blue food paste to make swirls in it. The filling is chocolate pudding with cool whip, and I used a simple syrup to keep it moist and fresh until Saturday...I used Wilton's ready to mix buttercream icing, sprayed the sides blue with the wilton spray paint, and made the music notes out of royal icing, that accidentally got left in the oven when we were preheating for something else, but actually it worked to our advantage because they are like hard as candy...