The morning that the music video for her new song “Rainy Day Woman” premiered online, Kat Edmonson had a revelation in the shower of her Brooklyn apartment.

“I was feeling so grateful for what I get to do,” said Edmonson, the 31-year-old singer-songwriter from Houston. She had just watched her video, which was directed by Robert Ascroft and was modeled after ’60s-style films like “Charade” and “Blow-Up.”

“It struck me how I’m still the same person I was in fourth grade,” Edmonson said, “the little kid playing dress-up, doing pretend photo shoots, writing songs in my bedroom and putting on plays in our living room. This is all just a glorified version of that.”

Perhaps the most enduring influence of Edmonson’s Houston childhood is stylistic. Like the pair of independent releases that preceded it, her first major label record, “The Big Picture” (Sony Music Masterworks/Sep. 30), is the result of years spent studying her mother’s record collection of film scores, classic crooners and big-band era jazz.

Edmonson attributes other hallmarks of her sound — like the way her songs mask their musical complexity with straightforward, conversational lyrics — to the years she spent honing her craft in coffeehouses, hotels and wine bars in Austin, Tex., where she played sets largely culled from the Great American Songbook, the canon of important 20th-century compositions (such as those by Cole Porter, Irving Berlin and George Gershwin).

During eight years in Austin, her “vintage pop” sound (she uses that description reluctantly) made her an anomaly, even in a town that prides itself on its musical heritage and diversity. And yet, over time, without so much as a real booking agent, she went from coffeehouse gigs to selling out large clubs and theaters. Her voice — singularly high and airy, yet elastic and expressive — also earned the attention of Lyle Lovett, who invited her to join him on “The Tonight Show with Jay Leno” for a duet of the holiday classic “Baby, It’s Cold Outside.” And later, after releasing her first album of original material in 2012, a largely Kickstarter-funded “Way Down Low,” she was asked to tape an episode of “Austin City Limits” on PBS. Even so, Edmonson decamped for New York in 2010, initially to split time between Austin and New York, only to leave Texas for good a few years later.

“In Austin, I was very niche, which is a great way to start my career because what I was doing wasn’t really being offered,” she said, “But it also meant nobody really knew what to do with me — how to help me take the next steps. And a lot of the music where I grew up studying and playing — stylistically — was born here in New York. There’s an underlying love and understanding of my style of music here. There was simply more people ready to help me business-wise.”

In New York, Edmonson signed with Mick Management, a firm that was instrumental in putting John Mayer and Ray Lamontagne on the map, and before long, they found a deal together with Sony Masterworks, who initially licensed “Way Down Low” for international release. Everything she had moved to New York for was in place, only Edmonson wasn’t as happy as she thought she would be.

“It was a tough process for me because I identified as someone doing it all by myself, me against the world. I drew a lot of strength from that,” Edmonson said. “I can’t underestimate how much that propelled me. Suddenly, there was all this support and a lot of cooks in the kitchen. Learning how and when to relinquish control and when to let people do what they need to do to help me was a confusing process. I was so wrapped up in being strong and doing this alone that I had to kind of grieve that in order to move on.”

Edmonson believes what’s made it easier to put her trust in the team she has assembled is that they are not put-off by the fact that the music she makes is hard to describe and thus more challenging to market. Is she a jazz singer? The next Norah Jones? Perhaps she’s a more modern Diana Krall? How radically different is she from Adele or Lily Allen?

“Some of my development in making this album has been in accepting who I am and finally believing there’s an audience for me — that if they get me, they get me and that’s who I’m playing this music for,” Edmonson said.

Even so, Edmonson believes she has given Sony something more commercially viable than her last album, “Way Down Low,” which was filled predominately with more intense, down-tempo material. “The Big Picture” is notably more energetic and jubilant. So far, Edmonson’s biggest champion has been NPR, which traditionally leads to slow-building, word-of-mouth sales. Even so, Edmonson says another big sea change in her outlook is that she’s less inclined to pore over the numbers or let herself believe any one part of marketing, touring or radio play surrounding this record is make or break.

“For so long, I needed to gauge the reaction of everything I did. I kept thinking I have to get to this place, or meet this goal. But I can now be open to however people receive it. I can just enjoy it, instead of wallowing in expectations.”