Jackson reunited with songwriting/production duo Jimmy Jam and Terry Lewis, their last collaboration being on her ninth studio album "20 Y.O." (2006). Additional songwriting and production was provided by Dem Jointz, Tommy McClendon and Thomas Lumpkins. Featured artists include rappers J. Cole and Missy Elliott. "Unbreakable"s theme reflects various experiences over the course of Jackson's life—including aspects of her childhood and the death of her brother Michael—in addition to socially conscious messages prevalent in her 1989 album "Rhythm Nation 1814". Its lead single "No Sleeep" became her 40th entry on the US "Billboard" Hot 100 singles chart, peaking at number 63, as well as her most successful entry on the US Adult R&amp;B Songs chart, topping the chart for twelve non-consecutive weeks.