The leadership changes at Pandora Media are taking place faster than expected: Today the company says that CEO Tim Westergren decided to step down, with CFO Naveen Chopra filling in as interim CEO.

President Mike Herring and CMO Nick Bartle also left.

In addition to relinquishing the CEO job, Westergren is leaving the board and will be replaced by Jason Hirschhorn. The CEO of digital content company the ReDEF Group is well known in media business circles from his work as MTV Networks’ Chief Digital Officer, President of Sling Media, and co-President of Myspace.

Pandora shares are down more than 1% in early trading. Yesterday they were up 2.2% after Recode reported that Westergren planned to leave once the company found a replacement.

Westergren, who co-founded Pandora in 1999, may have seen the writing on the wall early this month. SiriusXM — owned by John Malone’s Liberty Media — agreed to invest $480 million in the streaming media company for 19% of the stock. In addition, SiriusXM will control three seats on Pandora’s nine-member board, with one serving as chairman.

Westergren says he’s “incredibly proud ” of the company and reclaimed the CEO title last year “to drive transformation across the business.”

Having “accomplished far more than we anticipated,” he adds, “Pandora is perfectly poised for its next chapter.”

Board member Tim Leiweke says that Westergren “was quickly able to reset relations with the major labels, launch our on-demand service, reconstitute the management team and refortify our balance sheet by securing an investment from Sirius XM. We support Tim’s desire to identify a new CEO for Pandora’s next stage.”

The addition of Hirschhorn to the board, he adds, “will lend valuable counsel as we focus on driving long-term value for our shareholders. With this new addition to the board, as well as our recently announced partnership with Sirius XM and our sale of Ticketfly, we have added significant intellectual and capital resources to Pandora, and we are confident that the company is in a better position than ever to capture an increasing share of the music listening audience.”

Pandora’s value diminished as it struggled to keep up with streamed music competitors including Amazon, Apple, Google, and Spotify. Pandora reported a $132.3 million net loss in Q1, up 14.9%, on revenues of $316.0 million, up 6.3%.