Aretha Franklin has canceled a Detroit-area performance set for July 27, citing ongoing treatment.

The show at DTE Energy Music Theatre in Clarkston initially had been scheduled for June 22, but Franklin postponed it to later this month. Then, in a letter written by the Grammy-winning singer and distributed Friday by her publicist, Franklin says she was canceling the show “one last time” due to an unspecified ongoing treatment.

The 71-year-old Queen of Soul had announced in May that she was putting off scheduled performances in Chicago and Connecticut to undergo medical treatment.