Los Angeles, July 26 -- Kacey Musgraves has cancelled three shows from her upcoming Middle of Nowhere tour, including the Chicago concert that was set to open the country star's North American run, People magazine said.

According to the publication, the cancelled shows include the August 20 concert in Chicago, the August 29 show in Boston and the September 2 concert in Brooklyn, New York.

The three cities affected by the cancellations have multiple shows scheduled as part of the tour. Tickets are still available for the other dates, according to Musgraves' official website.

Musgraves, 37, has not publicly spoken about the cancelled shows so far. A representative for the singer also declined to comment when contacted by PEOPLE.

The Gra...