Chicago rapper Psalm One was born Christalle Bowen in the Windy City suburb of Englewood, where as a teen she sang in her church choir and studied a variety of musical instruments. She discovered hip-hop in middle school, witnessing fledgling rappers like Common and All Natural at local events, and while studying chemistry at the University of Illinois, she made her performing debut at a student union showcase. Adopting the moniker Psalm One, Bowen recorded her 2001 debut EP, Whippersnapper, during her junior year. She also guested on the Nacrobats' "Simply Beautiful," issued on the Pugslee Atomz-produced Chicago hip-hop compilation Network of Stars. Prior to graduation, Psalm One issued her first full-length effort, 2002's Bio: Chemistry, before returning to Chicago to work as a chemist in a food safety laboratory. She nevertheless continued to moonlight as a rapper, in the fall of 2002 joining the Nacrobats full-time in addition to issuing a solo EP, Personal Surplus. After the group dissolved the following summer, Psalm One continued collaborating with fellow Nacrobats alum Overflo, beginning work on her first record for new label Rhymesayers, 2006'sThe Death of Frequent Flyer. In the interim, in late 2004 the Birthwrite label issued a revamped Bio: Chemistry, titled Bio: Chemistry II: Esters and Essays, while the rapper toured as an opener for Del tha Funkee Homosapien.