Co-written by Rihanna together with its producers Terius "The-Dream" Nash and Carlos "Los" McKinney, it features guest vocals by American singer Chris Brown."Nobody's Business" is a house, disco-pop and R&B-funk song that mixes Chicago stepping and features strings, piano, and a four-on-the-floor kick drum.[21] Billboard's magazine stuff described it as a "wonderfully catchy throwback to early-90s club music",[22] while according to Dan Martin of NME is a swinging summer jam."[22] Stacy-Ann Ellis of Vibe magazine, wrote that the song, like the couple’s first post-makeup collaboration, "Birthday Cake (Remix)", is about the history they share and "refuse to let go of—it’ll irk some people".[17] Robert Leedham of Drowned in Sound stated that "Nobody's Business" "makes you want to write a long, worthy think piece so you can come to terms with your own moral standing on it.[15] Copsey of Digital Spy,[17] Ellis of Vibe and Leedham of Drowned in Sound agreed with Stern,[20] with the latter stating, "On an album that’s mildly abrasive and not a lot of fun, its piano-lead stomp and teasing vocal interplay are actually enjoyable.[16] Caramanica of The New York Times wrote that it is the most tender, affectionate, spirited song on the record, "On an album full of dyspeptic relationships, it is the breath of cool, nourishing air."[24] Jon Reyes of HipHop DX wrote that the song is "a very well thought out move, probably in hopes that it would help soften the impending criticism that Rihanna would receive from singing the pop version of makeup sex with her abusive ex-boyfriend.[30] Being more critical towards the collaboration, Randall Roberts of Los Angeles Times wrote that the track represents a sad inversion of the 1965 single "I Got You Babe" by Sonny & Cher, further noting " Instead of singing about connection, true love and wanting to shout it to the world, the song features a convicted abuser and the woman he assaulted asking everyone to shut up and leave them alone.