In the fall of 2019, Elizabeth Hart, best known as bassist for the band Psychic Ills, was pregnant and looking for a project that reflected this moment in her life. "I was interested in finding some way of collaborating with my physical state in a way," she says on a video call from Buenos Aires, where she and her New York-based family spend a few months of the year.

Hart is also a dancer, and earlier in her pregnancy, she had worked on some dance projects, but by her third trimester, the changes in her physical experience presented the most intriguing creative possibilities in that particular moment. "Luca was already moving a lot. My body was very full," Hart recalls. So, she and her husband, producer Iván Diaz Mathé, experimented in the recording studio.

Mathé had been working with bionsonic MIDI technology, which translates movement into sound, for a few years. In the studio, they connected the device to Hart's stomach and recorded the resulting music. That led to the album Sounds of the Unborn, which will be released via Sacred Bones on April 2. The album is credited to their daughter, Luca Yupanqui, who was born in November 2019.

Hart says that she found the recording experience to be meditative. "I just wanted to soak in the sounds in a way and the experience and just see what happened," she says. "Sounds would come in. Things would come in unexpectedly or the tracking would take a turn, and it was really interesting to hear the sound as it was happening. "

She describes the MIDI as working similarly to a polygraph, picking up information from both Hart's body and Luca's. "That technology is essentially writing the score," she explains, "so it's choosing which notes and the duration of time that the note is playing."

Hart and Mathé recorded the album over multiple sessions that were an hour to one-and-a-half hours in length and Hart describes that method as an "organic" process. "We were just seeing what sounds came out of this," she says.

In fact, an album wasn't the end goal when they began the project, but they came out of the recording sessions with hours of material. "After it was all said and done, we had a bunch of material recorded. We realized that we thought that we had an album there," she says. Then Luca was born and it wasn't until months later that the couple returned to the studio with their daughter to mix the album. They opted not to add any additional playing to the recordings. "There was some processing, maybe effects or things like that," says Hart, "but we wanted to be true to what was recorded."

That nearly hands-off approach to making the album is an important conceptual decision in the project. It's music made without the decisions of musicians. "It was not necessarily something that we may have chosen, had we been deciding what was being played," says Hart.

Instead, they were flexing their curatorial muscles. "That process was listening to a bunch of material and selecting the bits or the moments that we felt were interesting to us," says Hart of working on the mix. "Those parts are what became the songs on the album."

And, in re-listening to recordings, they made some interesting discoveries. "We would find things that we hadn't even remembered hearing at the time it was recorded because there was so much material," says Hart. "Towards the end, when we felt that we had everything, we went back through and listened to some more material and then we found something in there that we had passed over." Some of those sounds ended up on "V2.2," the video for which was released in late February. "It ended up being one of my favorite songs on the album," she says.

Sounds of the Unborn flows like a movie score, building and releasing tension over the course of ten tracks. It's full of whooshes and gurgles that give off the feeling of journeying into space or deep underwater - or perhaps, coursing through the human body.

"It definitely felt like material that I wasn't so used to working with," says Hart. "It wasn't intellectually chosen by us. It was really fascinating to work with. You don't go in there with a preconceived idea of what it's going to be. That was the really fun part of the process."

Hart and Mathé brought in various artists to help visualize the music. Martin Borini, who made the video for "V2.2.," also provided the album cover art. Artist Victoria Keddie used Super 8 film footage from the recording sessions to make the video for "V4.3 pt2," which was released earlier this year. Hart, who is currently finishing work on an album made in the honor of her late Psychic Ills bandmate Tres Warren, says that she and Mathé are in the early stages of follow-up to Sounds of the Unborn with various collaborators. "It would be kind of like a remix album, but not technically a remix album," she says.

As for Luca's reaction to the music, Hart recalls one moment in the studio when they were mixing the album. "She just made some face to us, looked to us, and we were like, does she recognize this?" Hart says. "She looked at us so knowingly."

Hart laughs, though, when she thinks of how Luca might respond to the album as she gets older. "She'll probably just feel like, you guys are so weird or something," Hart says. Still, she says, she's looking forward to her daughter's reaction.

Follow Elizabeth Hart on Instagram for ongoing updates.

Elizabeth Hart and Iván Diaz Mathé Turned a Studio Experiment Into Their Daughter's First Album