A 1990s hip-hop radio program that aired on Columbia University’s WKCR in the wee hours on Fridays was “the most important show in the world,” says rapper Nas. In the documentary Stretch and Bobbito: Radio That Changed Lives, that claim is supported by noting how, in that largely pre-Internet era, DJs Stretch Armstrong and Bobbito Garcia used their show to first showcase then-unsigned, now-iconic artists like Notorious B.I.G., Wu-Tang Clan, and a little-known performer called Jay Z. Directed by Garcia, this hip-hop head’s labor of love is an audio-visual autobiography, though he wisely includes a variety of voices, including those calling out the program for its misogyny and juvenile humor. While the movie doesn’t always make clear how this limited-reach oasis related to the music mainstream of the time, it nicely captures, through old video footage, the importance and excitement of the poetic freestyling and verbal battles that guest word slingers brought to the show. The film also documents how homemade cassettes of the show spread its message and the genre’s cultural role, and depicts Stretch and Bobbito as beacons for locked-up prisoners, graffiti taggers, and home-based fanatics of the evolving sound. The film shows at 6 p.m. at the Kennedy Center Terrace Theater, 2700 F St. NW. Free. 9202) 467-4600. kennedy-center.org.