In the music world, the saddest news of the summer so far was announced by Christopher Owens on Twitter today that he is quitting the Girls, the band he fronts and co-founded with JR White.

Since their start in 2007, Girls has grown as one of the most acclaimed San Francisco indie-rock bands in recent memory. Their debut record Album in 2009 attracted attention in the Bay Area and beyond. Their follow-up Father, Son, Holy Ghost, released last September, expanded the band’s popularity even more.

This morning Owens published a three-part tweet, stating “Dear all, This may come as a surprise to many & has been an issue of much thought to me. My decision was not easy to make. I am leaving Girls. My reasons at this time are personal. I need to do this in order to make progress. I will continue to write & record music. More will be announced soon. I thank you all for everything. Sincerely-Christopher.”

Owens’ personal, on-again-off-again battle with opiate addiction has been no secret, and neither is the history of his difficult upbringing in the Children of God religious cult. While the former Girls singer has admitted openly that the factors impacting his childhood are no longer impacting his his current outlook, Owens’ statement about making “progress” could allude partly to his struggle with drugs.

In an interview with Pitchfork following the release of Father, Son, Holy Ghost, Owens admitted that he wrote most of his songs “while heavily medicated,” though he also described his diligence in cleaning himself up before every Girls tour.

Owens’ announcement makes way for the question of whether Girls’ other half, bassist JR White, will continue to make music as Girls without him. No announcement has been made on the fate of the band yet, but it is certain that whichever way Girls goes from here, Christopher Owens’ delicate, whiny, and beautifully genuine vocals will be missed.