Rachael Yamagata’s 2004 album “Happenstance” was the 38-year-old’s big break, with songs from the album landing on shows like “The O.C.” and “Grey’s Anatomy,” known for turning under-the-radar tunes into hits. But for better or for worse, the album— full of breakup tracks — earned her a rep as an expert on heartbreak. Now, Yamagata is mixing things up with a new album in the works featuring songs with a different tune.

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“[Heartbreak]’s been my calling card for a number of years, for sure,” says the singer. “The songs on the new album are more based around someone’s personal journey of finding their passion, following their dream and keeping their spirits up.”

Questioning her career
Even as a seasoned musician, Yamagata finds herself debating again and again if she should stick with her career choice. “Some days I wake up with a slew of ideas and incredible energy for everything. Other days I question, ‘Should I stop? Should I find something new to do?’ It’s a constant revolving door of complete confidence and then totally insecurity.”

More than perhaps any of her other albums, the new album — out next year — is about soul searching. “The inspiration I had when writing the record was of a tight rope walker that really has to be in balance and experiencing these great highs and lows, the entire time taking a risk going through it,” she says.

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Celebrating the past
Yamagata is touring the country testing her new songs on audiences, but she’s also revisiting some of the old favorites that launched her career. In fact, she just wrapped up a special tour celebrating the 10-year anniversary of “Happenstance” and recorded an all-acoustic album of the songs.

“ I didn’t go back emotionally and feel how heartbroken I was,” she says. “It was a fun nostalgia.”

Positive vibes
She says in the past, it’s been much easier to write about heartbreak than happier times because it’s a channel for articulating painful emotions, helping diagnose exactly what the problem is, making it easier to move on from it. But now, she relishes writing about the sunnier side of life.

“The positivity of the new songs came very natural to me," she says. "And if it didn’t, it would have been another heartbreak album.”

Philadelphia
Nov. 13, 8:30 p.m.
Union Transfer
1026 Spring Garden St., 215-232-2100
www.utphilly.com

Boston
Nov, 14, 9 p.m.
The Sinclair
52 Church St., Cambridge
617-547-5200
www.sinclaircambridge.com

New York City
Nov. 17
Webster Hall
125 East 11th St., 5 p.m.
www.websterhall.com

Follow Emily on Twitter: @EmLaurence