Fontella Bass, the singer whose 1965 hit “Rescue Me” was an indelible example of the decade’s finest pop-soul, died on Wednesday in St. Louis. She was 72.

The cause was complications of a recent heart attack, her daughter Neuka Mitchell said.

Ms. Bass was born in St. Louis on July 3, 1940, and learned gospel at the side of her mother, Martha Bass, a member of one of the era’s major traditional gospel groups, the Ward Singers. From a young age she served as her mother’s pianist, but eventually, as an adolescent, got the itch to sing secular music. By the early 1960s she was playing with Little Milton, a blues guitarist and singer with links to the Chess label in Chicago.

After some early recordings with Little Milton’s Bobbin label in St. Louis, she joined Chess and released her first records on its Checker subsidiary in early 1965. The first two, “Don’t Mess Up a Good Thing” and “You’ll Miss Me (When I’m Gone),” duets with Bobby McClure, had modest success on the rhythm-and-blues charts. But her career was made by “Rescue Me,” released later that year.

Driven by a bubbly bass line, it featured Ms. Bass’s high-spirited voice in wholesomely amorous lyrics like “Come on and take my hand/Come on, baby, and be my man,” as well as some call-and-response moans that Ms. Bass later said resulted from a studio accident.