"Back It Up" is a song by Joan Jett and the Blackhearts. The lyrics talk about someone who constantly boasts about their worth and accomplishments, but in reality, they lack class and integrity. The song criticizes this person for trying to prove themselves to others, yet failing to back up their claims with actions. The song suggests that this person is insecure, and their attempts to impress others only reveal their true character. The lyrics imply that if this person could hear themselves, they would wish to be someone else. The song urges this individual to take the time to change their ways and stop wasting time talking nonsense. The line "He's a fag, come on change your act" in the lyrics is derogatory and offensive. It is important to note that this language is not appropriate and goes against promoting inclusivity and respect for all individuals. Overall, "Back It Up" is a critique of someone who talks tough but fails to deliver, ultimately urging them to show their true abilities and stop trying to fool others.