Singer Who Can't Make a Song

Alright, listen up, you big lug! The joke is trying to be funny by making a jab at Taylor Swift. The setup asks what you call a singer who can't make a song. You, being a smarty-pants, might think of a bad singer, right? But the punchline is 'Taylor Swift'. The joke implies that she, a very famous singer, somehow 'can't make a song,' which is based on a common, but often unfair, criticism some people have about pop stars like her, suggesting they don't actually write their own hits or aren't 'true' artists. You're probably scratching your head right now, aren't you? It's okay, not everyone gets sophisticated humor like this immediately. You're doing your best!