While big cities bustle with energy and ambition during the day, at night, behind all the glitz and buzz, a tinge of uncertainty lingers.

The city is where the singer-songwriter Lee Jin-ah explored the depths of her imagination over the past five years, delving into the different feelings a city harbors as its inhabitants try to endure and live their lives.

Lee's new album, "Hearts of the City," taps straight into the hearts of the people.

Through her new album, an extensive package of a dozen self-written tracks, Lee gently tends to the myriad emotions city life brings, and offers a place of solace.

The album's title is synonymous with "Hearts of Lee Jin Ah," the singer said during a recent interview with local media in Seoul on Monday.

"It's an album reflecting my heart. All the songs are based on my own stories."

It took five years for Lee to come out with a new full-length album, the first since she released her second LP, "Jinah Restaurant Full Course," in 2018.

It might have taken longer than five years, or not materialized at all, however, as the singer fell into a state of depression over the last year.

"Around the time I made 'Rum Pum Pum,' I was under pressure to make something better and keep on improving, which only made me slip further (into depression). Striving to always do well can take a turn for the worse," she said.

"Rum Pum Pum," a pop-jazz single released in January, was a huge hit, but Lee still felt lost.

It was in New York that she found some answers.

She went to local jazz gigs every night during her stay there, and one night, while watching a performance by legendary jazz-drummer Billy Hart, Lee said she felt a jolt of inspiration.

"I could feel his pure love for music. I'm not a drummer but his soul resonated with me. I was awestruck and I felt my pure passion for music reignite inside me."

The big lesson from her near two-month trip -- which also saw her stay for a short while in Paris -- was "to cherish every day like a gift," Lee shared.

Returning to her life refreshed and relieved of the stress that had once weighed down on her, everything became easier and more fun. Even the songs she had written for the album, but had shelved out of dissatisfaction, came back to her.

"I felt confident again and the album production process came more naturally. The focus was now not just on completing the album but on enjoying the whole process. It was physically tiring, but my heart felt light."

Fronting Lee's new album are two songs, "Skyline" and "Mystery Village," each reflecting her contrasting perceptions of the modern city. "Skyline," sings of a world packed with high-rise buildings, while "Mystery Village" is about Lee's hopes and imagination.

Lee likens the many screens we look at in the modern world to "mysterious mirrors" that affect people's minds and pull them away from their original dreams.

"The mysterious mirror in our hand affects our values. It might lead us to view the world differently without us even knowing it. I tell people to be brave and break free from it," Lee explained.

Lee's music is characteristic of its maker, not only in the brilliance of musical composition, but also in its benign, compassionate message. Her songs are bright but never simple as they always embrace the shadows of life and yield Lee's empathy and comfort, just as with "Mystery Village."

"(The song) conveys my wish that everyone could live with courage. I hope they soldier on on their path and don't fall out of it. The 'girl' I speak to in the lyrics symbolizes everyone male and female. I hope our cities could become more full with love."

The new album includes star-studded contributions by fellow musicians, including the nation's biggest K-pop name Lee Hyori and her husband Lee Sang-soon, who feature on the album's last track, "Words."

She originally planned to go solo for the song, a calm, minimal tune, but felt that Lee Hyori's voice would amplify its warm, healing energy.

"Just as I was thinking it was ridiculous because she is such a big star, the notification popped up on my phone. She'd left a comment on one of my social media posts saying my song 'calls to the soul.' I mustered up the courage and sent her a long, heartfelt text message. She told me her thoughts have also lingered on words words -- what we say -- and accepted."

Lee Jin-ah flew to Jeju Island, where the couple was living, and recorded the song with Lee Sang-soon, a music producer and guitarist, who played the guitar for the track.

Lee Jin-ah's longtime friend, Stella Kang, penned the lyrics for "End of the Journey," and also sang for the track, while singer-songwriter Sarah Kang, who Lee befriended on her trip, is featured on "City Lights." Cellist Hong Jin-ho also plays in "Dreams of Sadness" while producer Park Moonchi arranged "Sing!"

Images of singer-songwriter and jazz pianist Lee Jin Ah's third LP "Hearts of the City." (Antenna)

Having debuted in 2013 with her self-written album, "Invisible," Lee is celebrating her 10th anniversary this year. Looking back, the 32-year-old musician says she wants to give herself a pat on the back for coming this far.

"Although they weren't big steps that I'd taken, I want to acknowledge myself for always moving forward without stopping. I think it's commendable that I continued to write songs and hone my craft. I'm proud that, despite having suffered a slump, I didn’t give up and worked hard to stay on this path," Lee reflected.

"It's a big ambition, but I aspire to become an artist who can deliver her true feelings through music. It's not so easy now because I'm still quite tense (from the pressure to do well). I hope I gradually let myself be myself, and do my own music."

Lee is set to hold a standalone concert, "Hearts of the City," on Oct. 14-15 at Dongduk University Centennial Hall in Seoul.