It’s a nonprofit, run by its member songwriters, composers and publishers. And ASCAP came up with something called a blanket license in an effort to make the process simpler. It bases the rate on how many hours a store or restaurant that wants to play background music is open, or how many people listen to a radio network.

"Blanket license, meaning you can play as much ASCAP music, as often as you want," Williams said.

ASCAP had a monopoly on collecting royalties until 1940, when the radio industry, in a battle over rates, took all of the performing rights organization’s music off the air, says author Bruce Pollock. Radio stations replaced it with music that wasn’t licensed to ASCAP.

"Which was, like, country music and rhythm and blues," Pollock said. "And they started playing that. And, apparently, the public either didn’t know or didn’t care or didn’t complain, and it went on for eight months, until ASCAP finally had to renegotiate."

Meanwhile, the broadcasters had set up Broadcast Music Incorporated (BMI), and, over the years, signed new artists like Chuck Berry, Buddy Holly and the Beatles. ASCAP almost missed rock and roll entirely, and Pollock says it took a long time for them to catch up.

"It really took them until the mid-60s before they began to realize that, as they say, 'rock and roll is here to stay,'” Pollock said.

Sense of stability

ASCAP now represents close to 500,000 composers in all musical genres, and collects almost a billion dollars a year in royalties for them.

Valerie Simpson and her late husband Nick Ashford were among the top writers at Motown, before they went on to their own career as performers. Now a board member of ASCAP, Simpson says one of the most important things the organization does for songwriters is give them a sense of stability.

"You know, we just didn’t have to think about it," she said. "Some kind of check was going to come. You know, all we had to do was create."

One of her fellow creators is Pulitzer Prize-winning classical composer David Lang, who's been a member for 30 years. While the majority of his income comes from commissions and teaching, he looks forward to receiving his quarterly ASCAP royalty check.

"I get super, super excited when I open it up and I go, 'Oh, this piece is being played in Japan' or 'This piece is being played in Poland,'” he said. "I love the idea that the music can go someplace without me. And that I may not know about it, but, somehow, ASCAP finds out."

As it marks a century of protecting composers' interests, ASCAP faces new challenges in the digital era. The organization is currently in litigation with Pandora, the Internet radio company, over what rates to charge.