The “Rhinestone Cowboy”star, who released the album “Ghost on the Canvas” last year, will come back to the Birchmere on July 22-23, and tickets for those shows go on sale Friday. They’re part of Campbell’s extended farewell tour; he is giving up performing as he battles Alzheimer’s. Ticket holders for tonight’s show, you’ll get automatic refunds if you purchased online. You have until May 1 to get a refund at place of purchase. Tickets cannot be exchanged for the just-announced shows in July; those will have to be purchased separately.