Singer Natalie Merchant has postponed her sold-out San Diego performance tonight at Humphreys Concerts by the Bay, along with her Saturday show at Walt Disney Hall in Los Angeles.

Merchant, who rose to fame in the 1980s in the band 10,000 Maniacs, announced the postponements on her social media pages earlier this week. She has cited an unspecified illness as the reason.

The illness also prompted Merchant to postpone two other California concerts. Both had been scheduled for this week — Tuesday at Masonic Hall in San Francisco and Wednesday at Mountain Winery in Saratoga.

Three of her four postponed performances have now been rescheduled for next spring at the same venues. The new dates are: May 25 at Humphreys; May 29 in Saratoga; and May 30 in San Francisco. No new date has been announced yet for her pushed-back Saturday concert in Los Angeles.

Tickets for Merchant’s San Diego, Saratoga and San Francisco shows will be honored on the new dates. Refunds are available, through Oct. 28, at point of purchase.

Merchant 59, was diagnosed in 2019 with a rare, degenerative spine condition known as OPLL (short for ossification of the posterior longitudinal ligament). She subsequently had surgery to replace three deteriorated vertebrae. The operation left her without her singing voice for 10 months.

She returned this year with the COVID-19 pandemic-inspired “Keep Your Courage,” her first full album of original material since 2014. She began her 2023 tour in April. Her most recent performance was Saturday in Portland.