On December 26, 2023, two Kim Hyuk Guns stood on the same stage on JTBC "Re:Alive" (리얼라이브). One was Kim Hyuk Gun (김혁건) as he is in 2023; the other was the Kim Hyuk Gun of twenty years earlier, restored by AI — a digital twin.
This piece follows how "Re:Alive" built the digital twin, the stage it shared with him, and the 20th-anniversary songs released the same month.
01.The "Re:Alive" stage
"Re:Alive" (RE-ALIVE) is in effect the second season of JTBC "Alive" (얼라이브). Where the earlier season brought singers who had passed away back to the stage as virtual humans, "Re:Alive" chose a digital twin project that restores the peak years of singers who are still active. The subject of its first episode, on December 19, 2023, was Kim Hyuk Gun.
The project began with his own request. After watching the extended-reality performance of the late Lim Yoon-taek (임윤택) in the previous season, Kim asked the production team, "Make me with AI, too." On the program, Kim and Lee Si-ha (이시하) told the story of how they first met at MBC Academy and formed THE CROSS.
02.The technology that restored voice and appearance
An AI voice restoration company worked from Kim Hyuk Gun's voice data, training repeatedly to reproduce the tone of his peak years and his shouting that ranged above three octaves. An appearance restoration company recreated how he looked at that time through 3D modeling and de-aging — a technique that alters video data to return a person to a younger appearance.
The press launch was a showcase for the technology as well. It was held on December 14, 2023, on the metaverse platform Vikers (비커스), and reporters took part by logging on to the platform from dedicated PCs.
| Date | Stage | Details |
|---|---|---|
| — | Voice restoration | AI reproduction of his peak-years tone and shouting that ranged above three octaves, from voice data |
| — | Appearance restoration | Younger appearance recreated through 3D modeling and de-aging |
| 2023.12.14 | Press launch | Held on the metaverse platform Vikers |
| 2023.12.19 | First episode | Kim Hyuk Gun episode aired |
| 2023.12.26 | Joint performance | Stage by the digital twin and THE CROSS aired |
03.A joint performance of two voices
On December 26, the joint performance by the digital twin and THE CROSS aired. The voice that restored his 2003 range and the Kim Hyuk Gun of 2023 shared THE CROSS's songs between them.
Luna, N.Flying and Lee Mu-jin sang new versions of THE CROSS's songs, and Luna sang together with Kim Hyuk Gun.
At the press launch, Kim Hyuk Gun said, "Thanks to this, I was able to give a truly meaningful stage for my 20th anniversary, just like in the old days."
04.20th-anniversary songs from the same month
The broadcast also followed Kim Hyuk Gun, Lee Si-ha and the singer The One (더원), who joined as producer, as they made new songs. That song is "Poem of the Wind" (바람의 시), released on December 20, 2023. "To Reach You" (너에게 닿기를) followed on December 26.
The story of the two songs and "Don't Cry (2023)" is in THE CROSS 20th Anniversary Project, and the twenty years of "Don't Cry," which the digital twin also sang, are covered in Don't Cry: The 2003 Original and the 2023 Anniversary Recording.
05.Listen again
The 20th-anniversary songs are available on music streaming services and on THE CROSS's official YouTube channel, THE CROSS OFFICIAL. Subscribing to the channel is the fastest way to hear about new music. His other television appearances are listed in Kim Hyuk Gun's broadcast appearances.
What the technology restored was a vocal range from twenty years earlier; the one who sang on that stage was Kim Hyuk Gun as he is now.