OK I'll put my 2 cents in. " 50 years of rap" would make it 1972-73, right?
Sorry, but I don't remember that being around back then. I remember R&B, Soul, Funk, and Rock. You know, where you had to actually be able to play an instrument? Carry a tune? Harmonize? I remember THAT being referred to as music. Not rhymes in mono tone, scratching on a turntable, and spitting into a microphone.
But, like I said, "I'm an old guy".........