I added 'aint no other man' music to the animation and timed all the text layers to the different points of the song, i had to switch my song file from a mp3 to a wav. or Aiff. file so that they would work within my animation i switched it to wav. and once imported you could see the sound waves which made it easier to use so i would be able to see the waves and time it with the text layer. With a sound layer also you can fade in and out parts which means even if the sing is to long for the animation you can fade it out so it sounds like the end of the song, which i had to do.