Elton John discusses how Reginald Dwight became Elton John, and his realization years later that overhauling his persona had left him feeling empty inside, in this exclusive clip from his upcoming interview on Good Morning America.

During the interview, GMA's Robin Roberts asks John about his aversion to his birth name, both personally and as a budding rock & roll star. For John, "Reginald" was a "really old-fashioned name," and he hated the shortened version of "Reggie."

Famously, as John recalls, he constructed "Elton John" from the names of two of his bandmates at the time: "I was very clever," he quips. "I thought, 'No one's really called Elton, so I'll be Elton, and I'll be the only Elton.'"

Beyond distinguishing himself with an unforgettable name, John also says, "I wanted to leave my childhood and that persona behind." But as those decisions so often do, this one caught up with him years later before his famous show at Dodger Stadium in 1975.

"I realized I put everything into my work, and my art, and my recording, and there was nothing underneath it," John says. "I was just a void. And so I'd left little Reggie behind. But little Reggie was still inside of me, you know?"

John's interview with Roberts will air in full tomorrow, Dec. 11. It's pegged to the upcoming release of John's new documentary, Elton John: Never Too Late, which is set to arrive Dec. 13 on Disney+. The film -- directed by R.J. Cutler and John's husband David Furnish -- finds the musician looking back at his 50-year career in the lead-up to his final North American concert, which also happened to be at Dodger Stadium in Los Angeles.