NASHVILLE: Kelly Clarkson will reportedly marry her fiancé Brandon Blackstock in October. The couple will tie the knot on October 20 in Nashville, Tennessee, according to a Save the Date invitation obtained by Radar Online.”Bookmark the date for the wedding of Kelly and Brandon,” the note reads. “Formal invitation to follow.” Clarkson announced her engagement to Blackstock last December, describing his proposal as the “happiest night of [her] life”. The singer had hinted at an autumn wedding, confessing that she wants a “small” ceremony. Blake Shelton will apparently officiate at the wedding.–DS