The same way the deluge of horrid rap-metal in the late '90s sent throngs of appalled rock fans scurrying for the comforts of Led Zeppelin and the Beatles — sometimes for the first time — hip-hop's present creative rut makes any flashback to the genre's golden age not just a pleasant diversion from its current troubles but instrumental in preserving its cultural value. Also, real talk, the haircuts were a scream. To mark a solid generation of livening up Friday nights (10 p.m.-2 a.m.), KTSU's "Kids Jamm" program — one of the Houston area's first radio shows devoted strictly to rap, and still a vital resource for teaching aspiring jocks the tricks of the broadcasting trade — calls in a roster of boom-bap elders for an old-school party that promises to be even livelier than the flea market downstairs. One of Russell "Def Jam" Simmons's earliest discoveries — he was their manager well before founding his groundbreaking label — Brooklyn's Whodini laced their limber rhymes with a generous helping of vintage (even back then) funk and electro that, 25 years later, still prompts listeners to wonder, "Friends, how many of us have them?" Their NYC brethren Big Daddy Kane and Kool Moe Dee, meanwhile, continue to cast formidable shadows as two of rap's earliest and most influential alpha-male MCs, and ex-Geto Boy/former 97.9 The Boxx public-affairs host Willie D's politically charged gangsta grit provides some hometown Bayou City bump. Friday's festivities are both history lesson and block party, and so much the better.