Name of the song...

At the massage parlor two girls are arguing about the blackmailing scheme and one of them says "watch your back" and the other woman says, "Is that a threat? I imagine that it is." Directly after this scene it cuts to what looks like a club of some kind and one of the girls is seen talking to someone on the phone and there's this Arthur Lee and Love-esque rock song that plays in the background and the lyrics go something like, "No I told you don't you see you're free!" Does anyone know the name of this song? Does it exist? What's going on? Any help would be greatly appreciated.