Our deep dive into the credits for Beyoncé‘s liner notes turned up some gems, but I was particularly interested in Soulja Boy’s appearance because it illustrates just how strange the twists and turns of music industry fate can be. One day Soulja Boy is sitting at home, being a MySpace legend, and the next he’s got a shot at a GRAMMY for writing on Beyoncé’s album without lifting a finger, or a vocal chord. To walk through this quickly, “songwriting” is the art of crafting melodies and words for a song. Anyone who writes the words that appear in a song (and isn’t a ghostwriter) gets a songwriter credit, which…