Blind Item #7

This rapper/writer/singer/record producer used to be called in to a feature artist on songs. Now though, she is called in to just write the words she used to say. What are these words? She is known for casting spells. She got a huge reputation for rapping them, and big singers want the words, but not her on the song anymore because it brings too much attention. She was initially discovered by this A- list actor/showrunner/rapper/singer.