In an effort to combat violence, crime and disparity among plagued communities, the rap duo of Antonio Ennis (Twice Thou) and Edward Anderson (Edo.G) — together known as 4peace — have teamed up with Yale University Bands to offer Connecticut high school students the chance to perform original raps on stage. The “Rap 4 Justice Contest,” for which submissions are due today, challenges teenagers to write lyrics that describe a social issue without using obscene or violent phrases. The winner will perform his or her lyrical creations onstage to a backbeat and classical mix by 4Peace and Yale Bands in Woolsey Hall on May 6.