The musicians were drafted into the estimable organization, it was announced Wednesday, along with Darlene Love, New Orleans-based singer Dr. John and gravely-voice singer-songwriter Tom Waits.
Diamond, 69, who has been eligible for induction for years, had a measured reaction to the honor, telling the Associated Press in a new interview, "I thought about it occasionally, but I kind of figured they'd get around to me at some point."
Cooper, 62, was equally appreciative – but wasn't holding his breath for the announcement, either. "You know it crosses your mind, but then you think of all the guys who aren't in there, some of them before you," he said. "You realize that it's a waiting game."
Other eligible musicians for induction this year, like Bon Jovi, LL Cool J and Donna Summer, will have to wait until next year.