Billy Corgan Opens Up About His Friendship With Lisa Marie Presley and Performing at Her Funeral

The musician also spoke about performing at her funeral.

Billy Corgan is reflecting on his friendship with the late Lisa Marie Presley, and he admits there's one regret he has over his working relationship with her, or lack thereof.

During an appearance with The Smashing Pumpkins on SiriusXM's The Howard Stern Show, the rock band's frontman opened up about the tragic loss of Elvis and Priscilla Presley's only child, after she died in January at the age of 54.

Following her death, Corgan was among those who performed at her funeral, held at Graceland in Memphis, Tennessee, where he performed the band's 1998 single, "To Sheila."

"She was awesome -- that was a tough one," the 56-year-old musician said. "That was really hard for me because she was a one-of-a-kind person and the world really didn't know her because they, of course, always knew her as Elvis' daughter, but she was a really, really cool, unique person."

Corgan and Lisa Marie briefly worked together. He co-wrote the song "Savior," a hidden track off her 2003 debut album, To Whom It May Concern. Looking back, Corgan admits he regrets not spending more time working with her on that album after she requested his help.

"I wish I’d sort of taken more possession of it because she never really got her music thing off the ground," he said, noting he was too busy at the time to work more on that project. "She was actually really talented ... If you get a chance to hear her voice, she inherited a lot of her father’s great depth and the voice and it’s a shame that she didn’t make more music."

Corgan also opened up about having a "front-row seat" at getting to know Elvis like no one knew him, thanks to his close friendship with Lisa Marie.

"She did remember him, and she had really glowing things to say about her father," he said. "I got to know her father through her in a way that I’ve never seen him in public. So, I got this like front-row seat of what Elvis the person was like and, if you know what Elvis the person was like from her perspective, Elvis is even more amazing."

Corgan also offered his thoughts on Elvis' legacy, noting that some of the king of rock and roll's career choices -- like making "shlocky movies" -- put a damper on his overall legacy.

"If you look at it completely from a musicology point of view, he’s arguably the single most important music artist since they started recording artists because no one changed things more than he did," Corgan said. "His talent was at a level that’s almost incomparable ... but unfortunately, it’s mixed with a lot of things where people don’t see the talent because he just comes across as a personality."