Most independent musicians need a flexible day job - waiter, bike messenger, substitute teacher, cardiologist.

Wait a minute - cardiologist?

That's what singer-songwriter Suzie Brown is when she's not on stage. She works 60 percent of full-time hours at Albert Einstein Medical Center.

Despite her demanding other career, her musical talent has taken her to the top local venues, including the Tin Angel and the Kimmel Center, and she has opened for Lyle Lovett. She recently performed in Los Angeles and New York.

On Friday, she has a CD-release show at World Cafe Live. Heartstrings came out May 24.

Brown, 36, describes her music as "a cross between Norah Jones and Patti Griffin and Emmylou Harris."

Neither medicine nor stage performing is the sort of thing one just stumbles into, not at her levels of success.

In 1995-96, during her last year at Dartmouth College, the Boston expatriate, who now lives in Philadelphia, tried singing in the Dartmouth Rockapellas, an a cappella group, and realized, "Oh, my God, these are my people!" She taught herself guitar and continued pursuing music while at Harvard Medical School.

She has occasionally done a show the night after a shift at Einstein: "I would rather have to do that than not be able to do the show."

About switching back and forth between careers, she says: "The transition from medicine to music is not as hard as music to medicine.

"Music is so emotional. I feel I'm most who I am when I'm playing music, and then when I go back to the hospital, you have to be more impartial and professional and separate your personal life from your work.

"It's actually not good for patients if you're their friend. You have to be impartial and decide what's best for them, and sometimes it's something they don't want, something that hurts them."

Then it's back to music, where connecting emotionally with the audience is the point.

In another life-path detour, Brown earned a master's degree from the University of Pennsylvania in translational research, which helps put scientific findings into medical practice.

When she writes a song, "It always starts as something I want to say. . . .

"I always think of the hook, the crux of the song - what do people come away remembering? From the hook, I make the chorus, and from there, I write the verses. . . . In general, I always write at least some of the words before I write the music."

Her songs showcase her smooth fingerpicking and clear voice. Some are ballads with a dash of country twang, offset by the texture of lush chords. She can be bluesy at times.

"Heartstrings," the title track of her new album, channels Patsy Cline a bit, with a rich string arrangement.

As a girl, Suzie obsessively taped Top-40 songs off the radio to memorize the lyrics.

Her medical path comes as no surprise - she is the daughter of two doctors. In childhood, along with music, she threw herself into the incongruous combination of softball and math.

Her musical journey got bumped up thanks to an impromptu lark.

At a friend's wedding reception in 2009, she was goaded into jumping onto the stage, where she sang John Prine's "Angel From Montgomery," made famous by Bonnie Raitt and eventually an open-mike staple.

The crowd felt silent, and she realized this was quite a compliment: "It gave me that extra little bit of confidence I needed to take the plunge and start writing songs."

Now the fruits of her unusual journey will be echoing through the downstairs of World Cafe Live - all the way from that radio in her childhood bedroom in Boston.

Contact staff writer Robert M. Kelley at 215-854-4772 or bkelley@phillynews.com.