Glen Campbell pictured in 2012. Campbell and his wife disclosed in June 2011 that he had Alzheimer's disease.

Glen Campbell dies at 81

The Hollywood-handsome country singer with pop appeal whose long road to success gave special meaning to his best-known song had been suffering Alzheimer's disease.

Greg Allman performing last year. His final studio album is due to be released this year.

Allman Brothers' Gregg Allman dies, 69

Greg Allman was one of the principal architects of a taut, improvisatory fusion of blues, jazz, country and rock that became the Southern rock of the 1970s