Clue: Showing muscle, topless fashion in American battle scene (9)
Answer: LEXINGTON
Explanation: Definition: American battle scene
A charade of [f]LEXING ('showing muscle') minus its first letter ('topless', appropriate for a down light) plus TON ('fashion'). The battle scene might be in Massachusetts, for the opening battle of the Revolutionary War, or in Missouri, for either of two engagements in the Civil War.