Rap Music can be traced back directly or indirectly to where the music lyrics were spoken  at least in part rather than sung. Some blues songs back in the 60s and even a small handful of 70s songs some quirky like Jerry Reed's "When You're Hot, You're Hot". Musically the sound was funk, disco and R&B deconstructed down to its basic rhythms where voice became front and center and more integral than the instrumentation. Although rap didn't really take off until the 80s and beyond it was the Sugar Hill Gang's "Rapper's Delight" that put rap on the national map giving it mainstream attention and a following.