The album was initially planned to be more "energetic" than his previous work, but ended up presenting a wide range of styles such as R&B, pop, reggae, rock, disco, funk and soul music. Lyrically, Unorthodox Jukebox revolves around the theme of relationships, incorporating more explicit lyrics and subjects than his previous material. Critical response to Unorthodox Jukebox was generally favorable; many reviewers compared Mars's work to that of his previous album, while others deemed its lyrics shallow.