The history of rap music, all things considered, doesn't go back too far. The genre came out of New York in the late 1970s ...

From Pete Seeger to Billie Holiday to Rage Against the Machine to Kendrick Lamar, musicians of all genres have spoken truth to power ...

However, it's not so much that R&B has completely disappeared into a musical abyss but rather that the genre has changed over time ... a list of 25 of the greatest R&B songs of the '90s.