British siblings and music duo Wasia Project is touring the U.S. for the first time, and they say the exposure to new, larger venues is helping them develop their on-stage energy.

Brother and sister William Gao and Olivia Hardy are the opening act for Grammy-winning jazz-pop singer Laufey's tour, which stopped in Boston earlier this week for two nights at the Wang Theatre. The two performed their music that blends pop, jazz and classical influences, including a new song “Is This What Love Is?” and crowd favorite “Petals on the Moon.”

Gao and Hardy released their first music together in 2019. Their break-out moment came in 2023 when their piano ballad “ur so pretty” was featured in Netflix’s “Heartstopper” – a TV show centered around love stories between LGBTQ+ teens that Gao himself stars in.

On stage, Hardy takes center stage as lead singer while Gao sits at the piano. The two joined GBH News in between their Boston shows to talk about the dynamic of making music together as brother and sister, and what they’ve learned so far from touring with Laufey. What follows is a lightly edited transcript.

Haley Lerner: You’re in Boston right now, and performed last night at the Wang Theatre and you have another show coming. How has your time in the city been?

Olivia Hardy: Boston’s really fun. I'll be real. I really like the weather. It rained this morning as well, and that's the first time I felt like it rained for us in America on this tour. And it reminds me of home.

William Gao: Yesterday, I went for a walk in Boston Common, just opposite the theater, and it was just so nice to see people just enjoying that time and just like together, meeting for drinks, picnics and stuff. It's such an honor to play at this iconic venue.

Lerner: This is your first time touring in the U.S. How has that been for you?

Hardy: It's been different. We've never played sit-down venues quite like this before and of this scale and beauty. So, it's a very different vibe – America or not. Playing to American audiences, it's a very different and exciting thing for us that I found very warm and welcoming.

Lerner: Playing sit-down shows like this in venues like the Wang Theatre – does it make the performance feel more theatrical for you?

Hardy: It’s very, very, very different. We've come to learn a lot about how to bring our show to those spaces because the venue really does affect how a performance feels, even if it doesn't affect the show itself. We were in Europe and they were all like black box, very not pretty rooms. So, being in such a graceful environment definitely brings a sort of sincerity. Having people sitting was originally quite a shock for us, but it's been a huge learning experience.

Gao: As an actor, I love the theaters, so it's been really fun to play. A sitting down audience is always different from standing. The energy is just in a different space, but it's definitely influenced the performances and I feel like we've added some more kind of theatrical elements. It's quite fun. Our shows are already quite theatrical, but it definitely adds a layer now that we're playing in these wonderful theaters.

Lerner: Can you tell me more about your relationship touring with Laufey? William, I know you starred in her music video for “Goddess” (shot by “Past Lives” director Celine Song).

Gao: It started really organically. We hung out in London when she came over like a-year-and-a-bit ago. We hung out, and then she was like, “Oh, I'd love you guys to support me on tour at some point.” And then fast forward. It's so nice to have this tour growing out from a genuine connection of music and art. It felt really organic. We really respect what each other is doing like artistically.

Lerner: As a music duo, can you both talk about your relationship as songwriters and siblings? Is there a dynamic there that makes the process easier?

Hardy: We always say, as siblings, it's always nice to work in an honest and super comfortable environment because it's like a type of no-filter that exists. We know each other so well and that's what's really refreshing about it. When sharing ideas that we have that are personal and emotionally intense, it's nice to be able to share that with no stepping on eggshells.

Gao: That's definitely the environment that we create when we come together, whether that's songwriting in the studio or even on stage. Currently we're working on the EP, and each song brings its own process and its own kind of structure to it. But what remains constant is the space that we try to create and the energy we have as siblings. That is the constant.

Let's say we disagree, because everyone disagrees creatively. We definitely both understand that one of those ideas will be the right one. The main trust is that it's all going to work out, that trust is really big for me, it’s very comforting.

Lerner: William, you star in “Heartstopper.” How much of being an actor and that theatricality translates into your art?

Gao: Completely, I think especially in the music video space, but also in the studio, I feel there's definite links. Whereas as an actor, you're honoring a script, you're honoring a vision, and you're interpreting this vision. As artists, we have the vision and we are the vision and we want to create something. There's a definite link there, although they're very different crafts. When we were doing the “remember when” music video, I really felt like all of the craft of acting and interpreting was kind of there.

Lerner: “Ur so pretty” has been your biggest song, especially after being featured in “Heartstopper.” Is playing it live a moment that’s special for you?

Hardy: It's a very special song. I think it's very simple and beautiful. It is a moment where it's really delicate and it's been so beautiful performing that song in these venues. It's very raw. It's like it's just been written.

Gao: In our other songs and in our latest single (“Is This What Love Is?”), it’s very intense and there's a lot of sound and our band makes really big noise for a lot of the numbers. But “ur so pretty” is a moment where we can just really listen to a song in its purest form. And the beauty of that is really nice to share and to bring to people every night.

a girl sits on stage, touching her hair. In the background is a man on a piano.
Wasia Project performing at the Boch Center - Wang Theatre on May 7.
Haley Lerner/GBH News

Lerner: In terms of your stage presence and performing – Olivia, I notice you kind of take the lead when it comes to moving around on stage and interacting with the audience. How did you two figure out your dynamic and roles on stage?

Gao: It's all been very organic with the way we've developed the live shows. And I think when we tour the [upcoming] EP, we're going to explore even further. I feel everything that's come through with Olivia is wonderful movement on stage and the kind of the drama and the highs and the lows of the show, has come through. Each show is a learning experience, and we develop things always and constantly.