 The refrain is based on a Gm – E ♭ ( add2 ) – B ♭ – F / A chord progression . Fraser McAlphine of the BBC wrote that Rihanna feels confined " in a cell of [ her ] own creation " . She sings without vibrato , a pulsating musical effect used to add expression . One commentator , The New York Times ' David Brownie , wrote that despite this , her voice subtly shows grief and regret . Eminem then " zap [ s ] out into a ballady rap " : " I can 't tell you what it really is / I can only tell you what it feels like . " The verses follow a Gm – E ♭ ( add2 ) B ♭ – Fsus / A chord progression . Eminem regrets an end to an abusive , failed relationship , describing mutual violence and expressing both fondness and anger . The two artists ' characters are portrayed in a romantic relationship when he responds to Rihanna by concluding the verse : " I laid hands on her . I 'll never stoop so low again / I guess I don 't know my own strength . " Rihanna sings the chorus again , backed by an electric guitar and a piano . 
