British singer-songwriter Lianne La Havas talks with the same effervescence and graceful ease found in the songs on “Blood,’’ her delightfully assured second record released last summer. There’s not a hint of the typical pop-star false humility and self promotion when she speaks, so when she claims to be shocked about her first Grammy nomination for “Blood,’’ it feels wholly genuine.

“I was and still am completely, honestly over the moon just to be acknowledged,’’ the 26-year-old, who plays a sold-out show at Berklee’s Cafe 939 on Tuesday, says with an impossibly charming British accent, via phone from her London home. “It’s so wonderful to know that people are paying attention and the record is recognized in a world saturated by so many types of music.’’

In the ever bemusing world of the Grammy Awards (to be presented Feb. 15), the diverse, pure-pop “Blood’’ is nominated in the nebulous best urban contemporary album category. If La Havas’s music is urban, then Adele’s is dubstep. Let’s give the Grammy voters plenty of latitude and assume they consider the breezy, melodic songs of her second record “urban’’ because she lives in a big city.

“I actually didn’t even know what ‘urban’ meant,’’ La Havas adds, laughing slightly. “Whatever category it is, it’s a step forward for an artist like me. One of the most important things when I make music is I don’t want to be confined to boundaries and genres. I recognize calling it urban does insinuate my racial origin, but the recognition validates what I’m doing and it inspires me to continue to try and find the purest version of my sound, so it defies any type of racial stereotyping. My goal is to make the best music I can and however everyone else categorizes it that’s fine.’’

“Blood’’ is an artistic step forward for the musician born Lianne Barnes to a Jamaican mother and Greek father. “Is Your Love Big Enough?,’’ her critically acclaimed 2012 debut, was an acoustic-based singer-songwriter album consumed with relationships gone awry and betrayal. It was an often startlingly honest record filled with doubt and pain.

By contrast, her second effort has a bigger sound with a sunnier feel, assertive rhythms, and a more nuanced understanding of love. The singer is pragmatic about her growth. “I knew I needed to make a different record and honestly, I grew up a little bit, so there were new subjects and perspectives for me to write about. I’m still the same person with the same integrity, but you learn more about yourself as your life changes.’’

She cites a different reason for the obvious musical development, though. “Between records I reconnected with my Jamaican family on my mother’s side. On the trip I experienced a lot of things that made a profound impact on me. I absorbed elements of the culture and life while learning a lot about melody and beats.’’

Already, La Havas has emerged as a poised and powerful young singer who refuses to resort to cheap gymnastics or formulaic conventions. She’s not professionally trained, though, and didn’t take music seriously until her late teens.

“I sang in the choir at school, and friends and family were always encouraging me to sing, but I was always very shy,’’ she recalls. “I was 18 when I started playing guitar and wrote a song. That led to another song and then another — I knew then that was what I wanted to do. I found a manager and music lawyer on Myspace and it’s been a gradual process since then.’’

She pauses, contemplating the alternative. “I could never do a different job. I was always interested in art, but I took some art classes in school and just didn’t want to be taught how to draw. Luckily, I found happiness elsewhere.’’

She’s found unanticipated guidance, too. It’s no secret that one of La Havas’s biggest fans is Prince, who sought her out after hearing her music, ultimately leading to her dynamic appearance on his album “Art Official Age.’’ She says his influence has been profound.

“I’ve learned so much from him, most especially to not be afraid to not like something and to always follow your vision. Basically, he’s the boss and if he doesn’t like it, it doesn’t happen. He has a way of doing things that I admire and respect,’’ she says her voice perking up. “Working with him — and at first it all seemed slightly surreal to me — has changed my perspective on how to approach my music and career.’’

Ken Capobianco can be reached at franznine@live.com.