 In Britney Spears ' 2011 song " Till The World Ends " , Spears says " if you want this good shit " . However , on the official version , " shit " is reversed , creating the " ish " sound ; therefore , the official version says " if you want this good ish " . Backmasking is also used to censor the word " joint " in the video for " You Don 't Know How It Feels " by Tom Petty , resulting in the line " Let 's roll another tnioj " . 
