An early Google employee, Stone worked on the Blogger team after its acquisition, ahead of helping co-found Twitter in 2006.

He remained with Twitter for a number of years as the company grew to become adopted by millions of users worldwide. In 2011, as Twitter hit the 100 million active users mark, the entrepreneur left to pursue new projects with Obvious Corporation, a startup incubator and investment vehicle that had included fellow Twitter co-founder Evan Williams and former Twitter exec Jason Goldman. The venture most notably incubated the blogging platform Medium. However, in 2013, Stone and the others shifted their focus to individual startups. For Stone, that led to the creation of Jelly, a Q&A app and search engine that was later sold to Pinterest.

In 2017, Stone publicly announced he was returning to Twitter to lead strategic vision, brand, and culture, where he remained until 2021.

Over the years, Stone has also backed a number of companies, including Square, Pinterest, Slack, Nest, Intercom, and Beyond Meat, where he now chairs the Nominating and Governance Committee.

Stone said what initially appealed to him about the Swedish audiovisual company Chroma was its CEO and founder, Andreas Pihlström, who he met by way of an introduction from Pinterest co-founder Evan Sharp. Pihlström had previously worked as a creative director, design advisor, designer, and prototyper at Pinterest, Beats Music, and VSCO.

The two hit it off and began to have monthly calls after Stone’s angel investment.

“It’s really about finding people I enjoy working with and spending time with — and bouncing ideas back and forth,” said Stone.

The Chroma team had a range of ideas but ultimately landed on audiovisual technologies and their intersection with music and sound.

As Stone explains, the idea was about changing the nature of music and sound and making it a more interactive and immersive experience. In practice, this involves touchable, dynamic visuals that create a sound-driven digital space that users can explore and interact with for a variety of purposes.

The debut product to test this concept came out last year, through a partnership with music artist Arca to create an iOS app called Lux Aeterna. The app offers an audiovisual experience for exploring music from the Venezuelan producer, DJ, singer, and songwriter in a “meditative digital space,” the company said. Users fly through a virtual world, interacting with her music and sounds as part of the journey.

But this doesn’t show the full potential of the technology, which could have a range of use cases — some of which Chroma is now exploring — that demonstrate other ways users could interact with audio and sound, whether for play, meditation, relaxation, music composition, and more. While the company plans to first launch a product on mobile devices, Stone believes the technology could become even more interesting when and if Apple releases its own VR/AR headset.

“I think it’ll lend itself really well to the metaverse equipment when that’s more ubiquitous. But I can also see it on my Apple TV. I would love to have it on there. Anywhere there’s great sound and visuals,” he added. “Mobile [first] is just because that’s what everybody has.”

Founded in 2021, Stockholm-based Chroma last year raised $5.4 million in seed funding (5.1 million euros) from VC firms Singular and Adjacent, Berlin’s angel syndicate SpotiAngels, as well as other individual investors, including Stone and Pinterest co-founders Evan Sharp and Ben Silbermann. Chroma had previously raised 1.6 million euros in pre-seed funding.

As a board member, Stone expects to be meeting with the startup several times per month, in addition to the actual board meetings. He says that with his angel investments, he typically considers himself an advisor — meaning he’s open to founder phone calls but won’t call the company unless they want him to. Chroma did.

“These guys are brimming with different ideas [at Chroma]. So, the challenge has been to narrow it down because it’s a small team and to get something done they need to not do a whole bunch of stuff,” Stone said. For now, the focus is on adding a sensory experience to sound.

“The bigger picture is like this idea of ‘soundplay’ . . . it’s interactive. It’s changing the nature music so that it’s richer in a 3D way, but it’s also visual and . . . you can do things to it,” hinted Stone.

“Biz brings a wealth of experience in technology and design to our table. Together, we’ll pave a path to the future of sound: combining excellence in the digital space with forward thinking to shift the paradigm of music,” said Pihlström in a statement.

The board position isn’t the only thing Stone has in the works, as the entrepreneur says he’s been “noodling” on something else for himself with a small group of people. So far, the project is self-funded and hasn’t officially been launched, so he’s keeping the details quiet. However, Stone says he’s interested particularly in the emerging AI space and using AI as a tool, in particular.

He says he hasn’t been particularly interested in some of the other newer tech trends, like web3 or some aspects of the metaverse.

“The [web3] culture doesn’t appeal to me. There’s something off about it to me,” Stone explained. As for the metaverse: “I don’t want a dystopian future where kids are up in the room with a scuba mask on all day. I don’t want that to happen. That doesn’t seem good to me,” he adds.

As for Twitter, Stone admits he hasn’t been watching the situation as closely as others, but “it doesn’t seem good right now,” but said he wouldn’t make any future predictions. “Maybe it will turn out great, but it doesn’t look like it will…There’s so many people laid off and it just seems kind of chaotic…every day, there’s some new crazy thing — I mean, that was always true on Twitter, I guess. There was always something going on…this is a whole new level of that.”