This is why I love the interweb.
What we have here is footage of the Elektra Records "Hard To The Left" party that took place Dec 10th, 1990! The party features performance from the labels Hip-Hop roster including KMD, Pete Rock & CL Smooth, Leaders of the New School, and Brand Nubian. This is an industry party by the looks of it because the audience seems too cool to let loose, plus ATCQ, De La Soul, Funk Flex, Nice & Smooth, Run DMC, and a bunch of other rappers are all in the building. Basically a NYC record label party from the golden era of Hip-Hop! Big up DJ Iran for bringing this to the surface.
Brand Nubian's set above, Pete Rock & CL Smooth, Leaders Of The New School, and KMD's sets below.