"This would be my 28th year in a row," Love says, speaking to Billboard backstage at a charity concert honoring Joan Jett. "They never told me not to, but it was an unspoken thing. They couldn't ask me not to sing 'Christmas (Baby)' on another show, but after 10 years, then 15 years, of doing this one song on this one show, I felt I had an obligation to be true to them."
As anyone who's seen the Oscar-winning documentary 20 Feet From Stardom knows, Letterman helped restart Love's career with that annual holiday spotlight.
"Before that, I wasn't doing TV shows every year," Love tells Billboard. "Once I started doing that, others starting adding me in their Christmas shows, but I wouldn't sing 'Christmas (Baby).' Although I have five or six other Christmas songs I recorded with Phil Spector."
But don't think this means Love is retiring "Christmas (Baby Please Come Home)" from live performances.
"I called Paul [Shaffer] not too long ago and said, 'Well, what are we gonna do now?'" Love continues. "I said, 'I think we should get together once a year and do a huge Christmas show. A Paul Shaffer-Darlene Love Christmas show somewhere in New York.' I'm sure it would sell out."
Given Love's upbringing, it's fitting her most enduring hit would be a Christmas classic. Her father, a Pentecostal minister, banned rock n' roll from her house when she was a teen, calling it "the devil's music." But as the years went on, her parents warmed up to her career, and she knows her late father would be proud of her induction into the Rock and Roll Hall of Fame.
"My father would be so proud today," she says. "A lot of times the reason, especially my parents, [disapproved of my career] was because of church people and what they say. 'Your daughter shouldn't be singing that kind of music, her gift was given to her by God and she should serve God.' But I'm still serving Him," Love says. "It's just in another way."