LOS ANGELES — “You know where you’re not in normal time and space? You’re in the moment. Everything is really intense.” This is Susie Suh (pronounced “Sue”) attempting to describe what it’s like to be onstage singing and playing guitar. “I definitely can feel the adrenaline.”

The intensity is apparent in her facial expressions — eyes shut and head cocked, she gently strums and delicately picks at the strings on her acoustic guitar, crooning with a serene soulfulness that belies her 25 years. And when she discards the guitar’s heft from around her neck, Sean Hurley, who was playing double bass just moments ago, picks up another acoustic guitar, which leaves Susie free to throw herself into the next song, “Shell,” the first single off her debut album.

The packed crowd at the intimate Room 5 lounge on La Brea Avenue hangs on words that slip from between her full lips. When her set comes to an end, the audience responds with demands for an encore. They are treated to one more song.

It wasn’t always like this.

Three and a half years ago, before she had a record deal with Sony Music and a soon-to-be-released CD titled “Susie Suh,” she was just another singer-songwriter trolling the streets of New York City for any gig she could get. Small clubs, coffee shops, wherever and whoever would have her.

Susie Suh performs with Sean Hurley on double bass.

In the summer of 2001, before she was about to graduate from Brown University, she came to the Big Apple with a sense of purpose: could she make it as a professional musician?

“I mean … every moment was catered towards [music],” says Susie. “It was like a self-training kind of thing. I mean I was all alone, so I was just … I didn’t have any other distractions.

She crashed at her friend’s apartment, and spent her time writing songs or practicing and training her voice for about five hours during the day. She’d make fliers for upcoming shows or read books about the music industry. Then at night she would go to her gig or an open mic.

This was her routine for three months. “I was really, really determined,” says Susie. “It was a now-or-never situation. I really felt that if I didn’t get anything going that summer, I kind of wasn’t gonna do it. But I really wanted it. I just ate, slept, you know, and breathed music every day.”

Susie’s musical career began at an early age. Growing up in the Los Angeles suburb of Calabasas, her mother found something to keep her 8-year-old daughter busy on Saturday mornings: singing for the children’s choir run by the local Korean television station, KTE.

“My mom took me to K-town … every Saturday for a couple of years,” says Susie. “We used to do these commercials with hanboks, and sing [the Korean folk song] ‘Arirang.’” They even traveled to the East Coast to perform.