In a consolidated streaming music business, when most consumers get their music from just a handful of online outlets, could the tardiness of just one company’s data hold the Billboard album chart hostage?

That was the case this week, when a delay by Spotify caused the latest Billboard chart — still the industry’s most important scorecard — to be released two days late, a situation that industry chart watchers said was rare, if not unprecedented.

Billboard’s weekly charts, compiled from data collected by Nielsen, are posted every Monday, with self-congratulatory tweets from victorious artists and record labels coming soon after. When no chart appeared by Tuesday, Billboard published a brief note attributing the delay to “a top-tier data provider,” and offering no E.T.A. Nearly half a week’s data was missing, and the winner was difficult to predict because of a close three-way contest between Lana Del Rey, Meek Mill and Tyler, the Creator.

Billboard did not identify the truant account, but a Spotify spokesman acknowledged on Wednesday that the company was late, saying that “routine maintenance” had caused its delay in delivering data to Nielsen.