After living a relatively low-key life since their marriage in 2014, Ashlee Simpson and Evan Ross have been back in a big way since last fall. She, the former pop starlet, reality TV star and sister of Jessica Simpson; and he, a star on Fox show STAR and youngest son of diva Diana Ross, began with an idea to record an album of soulful love duets.

A documentary capturing their experience making that album turned into a full season E! pickup of Ashlee+Evan, chronicling not just the music but also their family life. For Simpson, it was a return to the medium that kick-started her career: first on her sister’s MTV show, Newlyweds: Nick and Jessica, and later with The Ashlee Simpson Show. Ross is no stranger to the screen. He had a recurring role in The Hunger Games films, as well as the 90210 reboot. Oh, and his sister is Girlfriends and black-ish star Tracee Ellis Ross. She and Diana Ross both made appearances on the new show, as did Simpson’s family.

Tying into the TV show and the six-song EP, Evan + Ashlee, is a gender-neutral clothing line that incorporates lyrics from their songs into the design. And this month, the two hit the road on their first joint tour and will play at Slim’s on Jan. 17.

Ashlee Simpson, 34, and Evan Ross, 30, made all of these moves at the same time, making them the Hollywood power couple about which you’re just now learning. It also meant the two would be spending all their time together for the foreseeable future.

“We always wanted to do this album together and then, finally, it was the right time,” Ashlee Simpson said, between tour rehearsals at their home studio in L.A. “I was either pregnant or he was on a show. … Once everything started going, it was inspiring.”

Simpson released three records between 2004 and 2008. Her debut, Autobiography, was certified triple-platinum, due in no small part to her TV presence. The chapter was marred by an infamous lip-synching incident on Saturday Night Live—one that in an era of social media would bolster fame rather than infamy. Like her debut LP, 2005’s I Am Me also debuted at No. 1 on the Billboard 200 chart, while a third, 2008’s Bittersweet World, reached No. 4.

Her last song to chart was 10 years ago. That year she left the spotlight to raise her son with her ex, Pete Wentz. Since then, she has acted in Chicago on Broadway on a few occasions. Simpson and Ross now have a 4-year-old daughter.

When she and Ross finally had enough time to collaborate, the floodgates opened.

“It’s funny how a lot of things just come together like that,” Ross said. “There was a lot of these ideas that kind of came together at the same time in a really nice way, luckily.”

Evan + Ashlee will surprise Simpson fans looking for a nostalgia kick. Instead of emo pop anthems like “La La” and “Pieces of Me,” they’ll find mature, sometimes sexy R&B grooves. There’s the flowery ballad “I Do,” funky and seductive “Paris” and “Safe Zone,” disco-flecked “Tonic,” bluesy “I Want You” and the acoustic, poppy-yet-reserved “Home.”

They are different from each other but similar in how they layer Simpson’s sultry rasp with Ross’ smooth vocals. The couple got Ross family friend, Earth, Wind & Fire bassist Verdine White, to play on all of the tracks and produce.

We spoke to both Ashlee Simpson and Evan Ross about the inspirations for these songs, working together and what they’ll be doing next: A second joint EP and solo records.

RIFF: All of your projects are intertwined. The TV show premiered the songs. The clothing featured lyrics. Was this primarily an artistic decision or business strategy?

Evan Ross: At the time, with a lot of these songs, there were little messages we were thinking of [for] the Zadig & Voltaire stuff we were doing. We were just adding our creative vibe to it, and I think at the time because we were writing songs, it came the easiest. It just made the most sense.

Your personal and professional lives are also mixed together. Is it difficult to live and work with each other 24-7?

Ashlee Simpson: No, it’s actually nice to do that. Usually, our work will take us somewhere different, or apart from each other, and it’s been fun to have this project together and get to share this time together.

Evan Ross: It actually makes things a lot easier than it would be being apart.

Evan, how did you and Ashlee convince your mom (Diana Ross) to be on the show? Did she need convincing?

Evan Ross: No, not at all. Everybody in my family knew what we were making. We were making a project around our album and sharing our lives in a way that felt special to us. It was an easy kind of a situation. It never felt like I was trying to force them to do anything; [if it did,] we wouldn’t do it.

Ashlee Simpson: Also, we wanted to do something about music and something that was a positive way to look into our lives.

Diana Ross helped you write one of the songs on the EP?

Evan Ross: It will be on the second part of the EP that we’re looking to release around February, but it’s a really special song that I’m excited that we’re doing. It’s her melody, and it’s amazing.

Which of your musical influences inspired Evan + Ashlee?

Evan Ross: A 1,000 percent, my mom. [Family friend] Michael [Jackson], of course, is a huge inspiration for me. We had Verdine White on this album, who produced on this record [and] was a huge influence on the sound of the music.

Ashlee Simpson: Yeah, he was amazing.

Evan Ross: A lot of this album felt like it was inspired by a lot of the music that we love from back in the day.

Ashlee Simpson: Yeah, it wasn’t just one sound, one genre. It was us being inspired by each other and kind of diving into a different sound for me, which was so much fun.

Ashlee, what have you learned from your previous reality TV shows that you were able to apply this time around—something you did or made sure to avoid?

Ashlee Simpson: It was definitely like, “Oh, gosh, I haven’t done this in a long time.” This time, we produced the show, and that was nice having that control. But definitely, back in the day, my show was something I do not regret. It was amazing for my fans to be able to go on that journey with me, and I felt the support from that.

When you last toured, you played pretty big shows. Rooms like the Roxy and Slim’s are considerably smaller. Are you ready to get so close to your fans?

Ashlee Simpson: Oh my God, yeah. Even before I did those tours later in my career, I was doing the Roxy, and I was doing both smaller and big venues. I’m excited for that intimate aspect of our show.

What can fans expect from your concerts?

Evan Ross: You’re going to hear the songs you heard on the EP, as well as Ashlee is going to be doing some of her hits from back in the day.

Ashlee Simpson: Yeah, I haven’t done these in a minute!

Evan Ross: There will be some fun covers, and also it’s really intimate and close.

Evan, you’ve written and recorded a few songs before, but are primarily known for acting. Will you be doing more in music going forward?

Evan Ross: Yeah, 100 percent. We’re putting out this next EP, and then we’re going to work on my album as well. She’ll be working on her solo album. It’s going to be really fun to … have a moment to play around with this stuff and kind of share the music. We’re excited.

What will your solo records sound like?

Evan Ross: We’re in the process of figuring that out. We’re already diving into what that will be. What’s fun is [how] the stuff we’re working on right now inspires the stuff that we feel like turning into something for our solo albums. I’m sure we’ll be helping each other in the process.

Follow editor Roman Gokhman at Twitter.com/RomiTheWriter.