I’d never really thought of using songs as monologues until one day at work I was asking a friend for ideas for a monologue for an audition. True to theatre-kid fashion he began reciting Eminem’s rap from “Love the Way you Lie” with Rhianna from a few years ago. It took me a few minutes to realize what he was doing. I was shocked because it was really really good.
That being said, I have never heard of anyone actually used one for an audition. Most of the auditions I do are cold reads and I don’t always need a monologue.
That being said, I’ve seen some really amazing ones. And they’re really good with rap songs. It’s a good way to stand out in an audition. Although people may think you’re incredibly weird.