PHILADELPHIA (July 3, 2013)--Demi Lovato has canceled her performance at Philadelphia's Fourth of July show because of a case of strep throat, city officials said.
"I can't sleep cause my throat hurts!!!" Lovato tweeted Wednesday.
Country singer Hunter Hayes, 22, will fill her place on the bill.
City spokeswoman Desiree Peterkin-Bell said officials are sad that Lovato can't play, but are glad to have Hayes as a replacement.
“He's that he's "one of the biggest stars in country music right now,” she said.
The city's annual Independence Day concert will also feature John Mayer, Ne-Yo, Demi Lovato and J. Cole along with hometown hosts The Roots.
Other performers include Philadelphia-born singer Jill Scott, as well as Grace Potter and Ben Taylor.