The only "rule" for music Ashley is that the music selection should in no way overpower the magic being presented. The music should complement, or work with but never outshine. For that reason many performers chose to use instrumental pieces, but that isn't necessarily the standard. Go with what you feel is right. Does the score bring something to the performance? Do your movements sync with the music? Does the lyrics hold an extra meaning when viewed with your performance? These are the kind of questions that when answered will help you guide you in your quest.
For floating rose, I'd consider this piece:
For a presentation that is reflective of a memory or a loved one that we get the idea isn't present with us anymore. Ignore the video. Just listen to the music. Imagine the scene.
Black stage. Single spotlight on center stage, a lone table stands, draped. On the table a blank picture frame, an empty candle holder, and empty vase. The performer walks on from stage left. He/she looks at the table and picks up the picture frame. Waves a hand over it and a picture of a pretty girl/boy appears in it. The performer sighs and sets the picture frame back down on the table. He/she plucks a "petal" of red colored flash paper from a flower on their lapel and ignites it with a match, a rose appears formed between the open fingertips as the flash paper burns out. The flower is placed into the vase, and the performer produces a silk from his/her finger tip to wipe a tear from their eye. From the silk a candle is produced, set into a candle holder on the table and lit. From there something marvelous begins to happen. The rose slowly begins to float, and hover around the performer as if guided by the spectral hand of the non present loved one. Hope sparkles in their eyes as they enjoy the moment. As the song comes to a close the rose is taken into the performers hands and the spell is broken. The performer places the rose down in front of the picture and walks off stage. Some how I can't shake the feeling that a snow storm belongs in here somewhere, but I'm not sure how to justify it. Anyways this is just something that ran through my mind.
http://www.youtube.com/watch?v=xj1Z3IF14qE