When Gary was growing up the Happy Days sitcom brought many of the 50's songs back to life. He fesses up to listening to his parent's old records and pretending to be Elvis Presley while singing The Devil in Disguise. 

While you may not know this, the title, at least, has a biblical connection.  In Second Corinthians 11:14, Paul warns the church that not everything that looks good is good. The devil is a master at making good look bad and bad look good. 

"And no marvel; for Satan himself is transformed into an angel of light."