There are more similarities than differences when it comes to preparation of a performance. You're using some lyrics, you have a relationship with them, they apply to different parts of your life and different circumstances, different memories, different stories you have in your head. You form personal relationships with the song. I think that's very similar, in a way, to prepping a character. You pour your own personality, in a sense, into the character, you sympathize with a character in a way that's similar to the way you might sympathize with a song.