Complex sentence: "Stormy Monday" has become so popular that one encyclopedia entry concludes "What bluesman does not have his own version?" Billy Vera wrote "rest assured, as you read these notes, someone somewhere is performing'Call It Stormy Monday'".
Split into simpler sentences: Stormy Monday has become so popular that one encyclopedia entry concludes "What bluesman does not have his own version?". Singer Billy Vera wrote "rest assured, as you read these notes, someone somewhere is performing'Call It Stormy Monday'".