"Born Under a Bad Sign" is an electric blues album, with influences of soul and funk. The album's music comprises simple chord progressions, which Jackson noted was due to inexperience. "We didn't know how to play it any better!" said Jackson. King played primarily on the three highest guitar strings and only used a select few phrases throughout the album. In the liner notes for the 2002 reissue of "Born Under a Bad Sign", critic Michael Point wrote how King was able to distinguish his guitar play despite only using a few phrases: "His simple but subtle reconfigurations were accomplished through inflections, emphasis, and timing, not via sprinting through scales."