If Medgar Evers rapped, he’d sound like KRS-One. Born a little more than two years after the World War II veteran and civil rights activist was assassinated by a white supremacist outside his home in Jackson, Mississippi, the man who entered this world as Lawrence Krisna Parker in Bronx, New York, has used rap to advance activism. As part of the seminal hip-hop group Boogie Down Productions, KRS-One, along with Public Enemy and others, defined political rap in the ’80s. Still fiercely determined, his 2015 solo release, “Now Hear This,” packs a mighty, righteous punch. His impressive and continuing body of work both on and off the stage is a testament to the wealth of inspiration that comes from lifelong commitment. KRS-One fights the good fight at the National on Friday, Jan. 22. Doors open at 7 p.m. Admission is $27-$37. thenationalva.com.