It’s a 15-second question that sometimes takes an hour to answer.

Who represents this artist? Does anyone know their publicist? Do you happen to know if they changed booking agents recently?

These are questions that anyone who has ever work in the music business knows well. In practice, tracking down an agent, publicist or manager has required a small fortune invested in out-of-date industry directories or the kind of insider access that takes years to build. For decades, that opacity was simply accepted as part of how the music industry operated — insular by tradition, opaque by design.

Mark Williamson, a UK entrepreneur who spent nearly a decade at Spotify, thought that needed to change. In 2019, he co-founded ROSTER — initially a database for music industry contacts and artist representation. Six years on, the company has evolved considerably, and today officially launched Rostr 2.0: a rebuilt, redesigned platform that’s both an "intelligence platform" and the front page of the music business

Williamson ran Spotify's artist relations team for much of his tenure, working at the intersection of the streaming giant and the industry it was reshaping. His co-founder, Adam Watson, was a senior software engineer at the same company. The founding thesis was direct: the music industry was already hard to navigate, and the arrival of new platforms, new genres, and an explosion in the number of working artists would only make it harder. "Over the next five to ten years, that's going to 10x the difficulty," Williamson told Decibel. That prediction has largely held up.

ROSTR launched its first product in October 2019 — six months before the pandemic shut down live music. It stayed lean, operating with just four people for its first few years. Rostr was eventually acquired by Utopia Music, a Swiss company on a buying spree in the music technology space, that went bankrupt in 2024. Williamson negotiated a buyback and ROSTR is now wholly and independently owned by its two co-founders.

At launch, around 95 percent of Rostr's data came from web monitoring — tracking artist websites, social pages, and trade pubs for signs of roster changes. Today, Williamson estimates that 75 to 80 percent of the platform's data arrives inbound: agencies, management companies, labels, and publicists proactively sharing their information. That shift reflects a genuine change in how parts of the industry think about visibility.

The platform's catalytic moment came early and by accident. Less than a year after launch, Williamson and a colleague looked at the freshly announced Coachella lineup and wondered what percentage of acts they had agency data for. The answer was around 60 percent. After a few hours of additional research, they redesigned the iconic Coachella poster — replacing artist names with the booking agencies behind each act — and included it in an outgoing email. Within hours, the graphic was circulating across industry Slack channels. Major agencies reached out, initially alarmed. Several years later, those same agencies are Rostr customers, and some now publish their own versions of the breakdown.

The episode revealed a strategic logic that has shaped the company since: surfacing data publicly creates a flywheel. Visibility drives attention, attention drives data contributions from industry stakeholders who want to be found, and those contributions improve the product.

"We've managed to convince decent part of the industry that sharing this information is good and positive," Williamson tells Decibel.

In the early days, that pitch was a harder sell. Some industry figures explicitly refused to share their client lists. The logic of keeping rosters private — protecting relationships, maintaining competitive advantage, preserving mystique — was deeply ingrained. Rostr's argument was essentially that the benefits of visibility outweighed those concerns: if you're an agent or manager, being discoverable by the brands, promoters, and labels looking to work with your artists is a competitive advantage, not a liability.

The platform now reportedly handles around 15,000 lookups per day, with approximately five million searches conducted in the past year alone. By Rostr's own accounting, those searches represent professionals across the live music world, the label sector, brand partnerships, and booking, all trying to identify and connect with the people behind artists they're interested in.

Rostr is no longer a contacts database with a single use case. Over the years it has added a jobs board — which Williamson describes as arguably the most-used in the music industry — a Yelp-style directory of service providers, a signings tracker monitoring upward of 5,000 to 6,000 deals annually, artist profiles aggregating team information and audience data, a festival directory, and Rostr Charts, which surfaces artists generating unusual spikes in platform attention, sometimes before news about them breaks publicly.

Previously, these features lived on separate websites with limited connectivity. Rostr 2.0 is largely an exercise in integration, pulling those data streams into a single interface. The platform also now includes New Industry Focus, a short-form music business news outlet launched about nine months ago, modeled loosely on the smart-brevity approach of outlets like Axios. Williamson's long-term goal is to make it the dominant trade publication for the music business — an ambitious target given the existing landscape, and one that will require substantially more original reporting infrastructure than it currently has.

Underlying the relaunch is a significant technical rebuild. The original platform was built incrementally over several years — Williamson describes it as adding extensions onto a house until the structure became increasingly difficult to work on. The new platform runs on React Native for Web via the Expo framework, which allows a single codebase to operate across iOS, Android, and desktop. For a 25-person, largely remote, customer-funded company, that architecture is a meaningful operational advantage, compressing development timelines and avoiding the cost of separate platform teams.

Williamson is candid about the structural challenges of music technology as a business. The market is not large enough to support venture-scale companies, and many music tech startups have raised heavily, built impressive products, and found themselves unable to generate returns that satisfy investors. Rostr's approach has been deliberately measured: grow organically, stay independent, and build sustainably. "You have to be really careful with music because it can be tough," he said. The company's primary revenue comes from individual subscriptions, with enterprise accounts — reportedly around 400, with its largest customer holding some 600 seats — layered on top.

For a platform that aggregates sensitive data about industry relationships and personnel, neutrality is not an abstract concern. Williamson describes declining approaches from companies proposing publishing joint ventures and label deals that would have created financial incentives beyond subscription revenue. He also describes the weekly requests from industry professionals asking how much it costs to appear on Rostr's trending charts — requests the company says it declines. "Everything we're trying to do is deeply independent," he said.

narrowsThere are structural tensions, nonetheless. The platform's charts reflect algorithmic choices that are not fully transparent to users. Its data is heavily dependent on voluntary contributions, meaning companies less forthcoming with information are likely underrepresented. And a news outlet that reports on the same industry it depends on for data creates an inherent complexity that will require ongoing navigation. These are not unique challenges in the data platform space, but they are ones a company explicitly positioned as neutral will need to address with rigor as it grows.

Williamson's long-term framing reaches for the Bloomberg terminal analogy — a unified dashboard that music industry professionals open each morning for news, contacts, trending artists, job listings, and deal flow. The gap between that vision and Rostr's current capabilities is real. Dedicated data platforms remain more comprehensive for deep analytics; established trades remain better-resourced for original journalism. What Rostr is positioning itself for is the generalist middle ground: a functional amount of all of it, organized around the people and relationships that structure how the music business actually works.