After choosing my track I went on to cut it in Audition. I noticed when working with the track in Audition that there was a small part at the ends, that represented something ending it was soft. I thought it would be perfect for the frames where the Snow Child dies and melts.
I now just need to work out how I use it with in Flash. I want it to only play on these frames, so this will be the challenge.
For now the best way for me to do this is to just cut the clip to the same amount of time that the movie clip is playing. I think the may be a better way and will research this.