WASHINGTON, DC - MAY 16: Glen Campbell performs during the Alzheimer's Association Evening with Glen Campbell at The Library of Congress on May 16, 2012 in Washington, DC. (Photo by Kris Connor/Getty Images)
LOS ANGELES, CA - FEBRUARY 12: Musician Glen Campbell performs onstage at the 54th Annual GRAMMY Awards held at Staples Center on February 12, 2012 in Los Angeles, California. (Photo by Kevin Winter/Getty Images)
NASHVILLE, TN - JANUARY 03: Glenn Campbell performs during The Goodbye Tour at the Ryman Auditorium on January 3, 2012 in Nashville, Tennessee. (Photo by Ed Rode/Getty Images)
NASHVILLE, TN - SEPTEMBER 19: Glen Campbell performs on SiriusXM's Elvis Radio and Outlaw Country channels in SiriusXM's Nashville studio on September 19, 2011 in Nashville, Tennessee. (Photo by Rick Diamond/Getty Images)
SYDNEY, AUSTRALIA - JANUARY 30: Musician Glen Campbell poses during a photo call at the Shangri-La Hotel Sydney on January 30, 2008 in Sydney, Australia. (Photo by Gaye Gerard/Getty Images)
BEVERLY HILLS - SEPTEMBER 12: (L-R) Recording artists Glen Campbell, Dionne Warwick, Whitney Houston and producer Clive Davis pose for photographers during the15th Annual Ella Awards at the Beverly Hilton Hotel on September12, 2006 in Beverly Hills, California. (Photo by Frederick M. Brown/GettyImages).
LOS ANGELES, CA - JUNE 18: Glen Campbell plays at the Ray Charles Funeral service held at the First AME Church Los Angeles on June 18, 2004 in los Angeles, California. (Photo by Genaro Molina-Pool/Getty Images)