Although “What’s Going On” was inspired by Four Tops member Renaldo Benson’s account of police attacking anti-war protesters, it’s not a protest song per se. Rather, it’s a deeply human plea for love and brotherhood in the midst of a turbulent world.

Marvin Gaye’s voice is that of an angel, crying out “Oh, you know we’ve got to find a way/To bring some understanding here today” while Motown’s legendary Funk Brothers ensure that the song swings.

Motown founder Berry Gordy initially dismissed the song, allegedly calling it the worst thing he’d ever heard in his life. But when it was released behind Gordy’s back, it became the label’s fastest-selling single ever.

The follow-up album, released several months later, expanded on “What’s Going On,” blending socially conscious lyrics and spiritual themes with rich arrangements and funky grooves, and is widely considered one of the greatest albums of all time.