A late-'70s disco-funk anthem didn't just light up dance floors. It helped launch an all-female family group into stardom. Sister Sledge quickly became a standout singing group of the disco era, ...

Ah, the '70s—a time when disco balls sparkled, bell-bottoms swayed, and music truly had its own funky heartbeat. It was an era of experimentation, and while many artists flourished, some only managed ...