Over the course of nearly two decades, Kim Yong-jun of vocal group SG Wannabe has gone from a fresh rookie to an industry veteran who has scored multiple megahits. But he describes himself as a "no-hit wonder" because there’s nothing that he can present as a soloist.

Now, Kim seems to be ready to branch out with his first-ever solo album, “Suddenly,” which released Friday evening.

“I’m nervous but excited at the same time about dropping my first album, and I’m satisfied with how the outcome turned out,” the singer said in an interview with a group of local reporters in Gangnam, southern Seoul, on Oct. 5.

Kim debuted with SG Wannabe in January 2004 with the band’s megahit “Timeless.” Since then, the trio has risen to be an A-lister group, notching artist of the year awards at music festivals.

Although Kim has a long list of accolades under his belt with SG Wannabe, working on the album started from a fresh, clean state because he wanted to show a different side to listeners. If his first solo single, “Beautiful,” which released in January, carried SG Wannabe’s bright ballad music style, this time, the singer opted to tweak his musical palette.

“Since it’s autumn, I thought of wanting to put out a sad ballad song that would suit the season. Ballads could sound similar in some ways, but my kind of ballad is the retro sounds that were popular in the early 2000s,” the musician said.

Kim went on to say that, hopefully, his first solo album would trigger many people’s memories of those times, saying he fell into his music so much. The singer also pinned his hopes on bringing a flash from the past.

“The central keyword that rounds out the album is ‘separation,’ where it talks about how love hurts. That’s why the namesake titular is ‘Suddenly,’ because there are times when your past lover or memories suddenly pops up in your mind. I wish people would walk down memory lane by listening to my songs.”

The words to the music are straightforward: It’s about how one will not be able to forget their lover, which is how the artist wanted to express a breakup. He added that the song’s melancholy melody also carries a lot of emotional baggage, saying he choked up while recording it.

Kim also offered an insight into his solo musical approach.

“As corny as it sounds, I wanted to show who ‘Kim Yong-jun’ is as a soloist, and I want more people to know about my music (when they hear the new album),” he said, adding that he had tried hard to meld in his music style and emotions in his music.

“It’s a little embarrassing, but I have a thin and high-tone voice, so I thought the facets that would make up my traits would be the bitter and heartbroken emotions that my voice can make,” he added.

When asked why it took nearly two decades to work on a solo project, Kim said the main importance of his career was promoting himself and making music as SG Wannabe, not a soloist.

“But I’ve realized that fans have been waiting for my solo projects, and some of them kept on asking me if I had plans to do so. Now that I think of it, I feel bad, and I knew that I had to drop a solo album for my fans before it got too late,” Kim said.

Despite any concerns, Kim is enjoying his new independence.

“I gave a lot of thought while working on the album, figuring out what I should do. But I have no regrets. I’ve put that much effort into it,” the singer said, gushing about the album.

Kim’s solo debut could carve a new path for another decade-plus career of his own, but the singer made it clear that he’s not waving goodbye to SG Wannabe, saying it’s a place he belongs.

“I don’t want to bite off more than you can chew. I don’t want to re-create the glory days I experienced before as SG Wannabe, but I hope that people will remember that there was a group called SG Wannabe and Kim Yong-jun. I hope my music will be remembered for a long time.”