Singer Glen Campbell performs during his Goodbye Tour in Little Rock, Ark., on Sept. 6, 2012. (AP Photo/Danny Johnston)
** FILE ** In this Sept. 6, 2012, file photo, singer Glen Campbell performs during his Goodbye Tour in Little Rock, Ark. Campbell finished off his Goodbye Tour on Friday night, Nov. 30, 2012, in Napa, Calif., but is considering scheduling more dates in 2013. The singer has Alzheimer's disease. (AP Photo/Danny Johnston, File)
** FILE ** In this Sept. 6, 2012, file photo, singer Glen Campbell performs during his Goodbye Tour in Little Rock, Ark. Campbell finished off his Goodbye Tour on Friday night, Nov. 30, 2012, in Napa, Calif., but is considering scheduling more dates in 2013. The singer has Alzheimer's disease. (AP Photo/Danny Johnston, File)
This July 27, 2011 photo shows musician Glen Campbell in Malibu, Calif. . Campbell, who was diagnosed with Alzheimer's disease is planning a farewell tour before retiring from the music. Campbell is canceling the Australia and New Zealand stops of his "Goodbye Tour" with Kenny Rogers next month for health reasons. (AP Photo/Matt Sayles)
This July 27, 2011 photo shows musician Glen Campbell in Malibu, Calif. . Campbell, who was diagnosed with Alzheimer's disease is planning a farewell tour before retiring from the music. Campbell is canceling the Australia and New Zealand stops of his "Goodbye Tour" with Kenny Rogers next month for health reasons. (AP Photo/Matt Sayles)
Country-pop singer Glen Campbell, who is battling Alzheimer's, performs Feb. 12, 2012 at the 54th annual Grammy Awards in Los Angeles. (Associated Press)
** FILE ** Kimberly Perry, left, Glen Campbell, center, and Reid Perry perform during the 54th annual Grammy Awards on Sunday, Feb. 12, 2012, in Los Angeles. (AP Photo/Matt Sayles)
