The Kennedy Center celebrates a second year of free live performances tonight with two ’70s hitmakers who last rubbed elbows on Vol. 2 of the Boogie Nights soundtrack, Randy Newman and KC & the Sunshine Band. Newman, represented on that disc by Three Dog Night’s cover of his “Mama Told Me Not to Come,” and perhaps best known for his misunderstood ’77 hit “Short People,” has joined former Oingo Boingo frontman Danny Elfman as a songwriter-turned-distinguished-film-scorer, receiving three Oscar nominations for his soundtrack work this year. KC and company’s Boogie Nights contribution, “Boogie Shoes,” is not among their three No. 1 hits included on Rhino’s recent Disco Box, which correctly credits them as one of the “pistol-hot rhythm bands” that stoked the disco inferno. Though you’ll have to show up to see this show, beginning April 1, Millennium Stage concerts will be broadcast daily on the Internet and archived for on-demand viewing. At 6 p.m. in the Kennedy Center’s Grand Foyer. Free. (202) 467-4600. (Daniel Searing)