Billboard reports that a "heartbroken" Robyn says she just can't perform songs on which she collaborated with producer Christian Falk, who died last summer from cancer.

That's led the pop artist to cancel her appearance at Treasure Island Music Festival and one other engagement. But there's good news, too. Next month she'll be ably replaced by another dramatic electro-pop singer, this one the young, rising London talent FKA Twigs.

For a refresher, here's the rest of the lineup.

"It was much harder singing these songs on stage than I thought,” Robyn said in a statement. “Even though it's been a year since Christian passed, I'm heartbroken and performing them feels too heavy still. I'm sorry to disappoint the fans that have bought tickets to these shows, and I will do my best to come back to San Francisco and Brazil soon.”

FKA Twigs, who is engaged to acting person Robert Pattinson, followed up two EPs with a debut album, LP1, released last August. That's gathered to it huge buzz over the last year, and should make for an exciting show at TIMF.

Previously: Here Are The Official Treasure Island Music Festival Night Shows (So Far)