Final answer:
The phrase 'Music with a fast tempo and upbeat lyrics' is not a complete sentence because it lacks a subject and an action.
Step-by-step explanation:
The word group that is NOT a complete sentence is 'Music with a fast tempo and upbeat lyrics.' This phrase lacks a subject performing an action, and thus, it is not a complete sentence. Instead, it is a fragment describing a type of music. Every sentence should have at least a subject and a verb to be considered complete. In this case, the group of words fails to form a complete thought, making it the correct answer to the question.