Glen Campbell has closed the Nashville office of GC Enterprises, and longtime Campbell executive Marty Gamblin has left the company. Campbell's manager, Stan Schneider, will continue to conduct business from Campbell's Los Angeles office; Schneider also manages Bryan White. Gamblin currently manages South Sixty Five and Katy Benko. "Marty has been a good friend and a valuable asset to Glen Campbell Enterprises for many, many years," Campbell says in a news release. "We wish him great success."