Hip hop has been a long way, and even though I don't like where it is right now, it has seen some amazing artists over the years. From MF Doom to Death Grips to The Sugarhill Gang, what was just a small underground movement has blossomed into the mainstream. And while mainstream hip hop at large may be dwindling in quality, there is still an abundance of amazing popular hip hop artists out there right now like Sampha with Process, Jay-Z with 4:44 and many others.
Without hip hop, there would be Tupac, no Eminem, no Nas, no N.W.A, no rap at all.
So yeah, hip hop had a cultural impact.
But all of this is nothing compared to what it really did. It opened up music making to a class of people who couldn't afford to make music before. And that birthed, or at least aided the rise of the underground music scene. Sure, there was underground scenes before like punk and post-punk, but hip hop helped evolve the underground to where it is today, where anyone can make music.
HAPPY 44TH BIRTHDAY, HIP HOP!
P.S. Go play the google doodle, it's awesome. It basically teaches you how to mix and use turntables. It's great fun.