Gwen Stefani recently returned to her ska and reggae roots on "Let Me Reintroduce Myself" and "Slow Clap," and it looks like she's got a full album on the way in that style. She spoke about it in a lengthy interview with Ryan Leas for Stereogum:

I had this idea I would go back and do reggae music again because I was thinking so much about it. My son is 14 and he’s discovering it. I remember that age where you’re like, “I’m into ska, that’s who I am, I’m not like everyone else at this high school.” Once I told the people I was starting to collaborate with that that was the direction, it was sort of a wildfire. Everyone was so into it. The songs were coming out so easily. For me one of the worst things ever is trying to be vulnerable. Like, I don’t know how to write songs. I don’t know how I’ve ever written one song. And now I’m going to go in with someone I don’t know — in a Zoom — and I’m gonna be like, “My kid’s in the next room,” and I’m going to try and write a song in the next three hours? It’s scary. But that’s how it started.

[...] The intention of this whole album was to write music that was nostalgic to the people who actually did follow me all these years, that they could listen to it and it’d be new but it’d be familiar. I thought about them. If they didn’t listen to it, why else would I do it? So I’m doing it for them, too, you know what I mean? But yeah, I feel like that song is fun, uptempo, not serious but it has serious things in it. It’s all about saying, “Are you rooting for me like I’m rooting for you?” I’m really happy I got to write this song with Ross. The fact that the label wants to put out such a weird song, I’m clapping for them. [Laughs]

She also spoke about her days discovering ska as a teenager:

For sure. We went really far into that actually. When I first started thinking about doing music, it was right around the time the riots were happening. When I discovered ska music, in the late ’70s it was all about unity and anti-racism, good skinheads and bad skinheads. We thought at 17, 18 — not that we were going to save the world, but we were kids, we didn’t know — but we were trying to imitate this other generation and they were so vocal about their message. We heard that.

I started investigating all these different documentaries about ska. It was a full circle moment for me, and I thought that ska and reggae music is a place where you can have fun. No matter where you go in the world they’ll play reggae. You can be spiritual and emotional and political all in this genre. It just felt like the right place for me to be. All these ideas… it reveals itself. In eight weeks, I think we wrote most of the record. Twenty-five songs or something.

She also spoke about her past collaborations with Prince and Eve, her much more recent collaboration with Dua Lipa, the Madness-inspired 1992 video for No Doubt's "Trapped In A Box," and much more. You can read the full interview here.

Gwen expanded on how the current political climate and the recent 25th anniversary of No Doubt's Tragic Kingdom inspired to get back to her ska roots in an interview with L'Officiel too:

It's a combination of things that brought me to the sound of this new single. The 25th anniversary of No Doubt's album Tragic Kingdom has played a part. There's also everything going on in the world, #metoo and racial issues. We were already talking about that with No Doubt, through the ska music of the '70s which highlighted unity and anti-racism. I have a teenager at home who also listens to a lot of music. It reminded me of who I was at 14-15 years old and made me want to deepen my work around the music that defined me: ska and reggae.

She also sort of touched on the idea of a No Doubt reunion in an interview with Zane Lowe for Apple Music. Zane asked if Gwen has been thinking about the upcoming 30th anniversary of No Doubt's self-titled debut, and she said, "It is a really big deal, and I do, I'm reflecting so much on all the music. When you're writing new music, reflect on everything that you've done." She then added, "I have no idea what the future holds with that." As Us Weekly points out, bassist Tony Kanal said in 2017, "I think we’re on an indefinite hiatus right now. I would say we will definitely play at some point, but there haven’t been any plans or anything." So, maybe it'll happen? Stay tuned.