New Kids on the Block: "(You've Got It) The Right Stuff" ("Tonight" is the opening line of this song)
The Police: "Roxanne" ("Roxanne, you don't have to put on the red light"/"Those days are over, you don't have to sell your body to the night")
David Bowie: "Life on Mars?" ("...look at those cavemen go,/It's the freakiest show...")
Journey: "Separate Ways (Worlds Apart)" ("Tonight the music seems so loud,/I wish that we could lose this crowd")
The Commodores: "Easy" ("Easy like Sunday morning...")
There are many other songs titled "Tonight." Which song are you looking for? Please provide more details, and I'll do my best to help.