Country music legend Glen Campbell, the "Rhinestone Cowboy" who sold millions of albums over a career that spanned decades, has died at the age of 81 after a long battle with Alzheimer's disease, his family announced Tuesday.

"It is with the heaviest of hearts that we announce the passing of our beloved husband, father, grandfather, and legendary singer and guitarist," the statement said.

In June, Campbell -- a fixture on country music charts since the 1960s -- released his final album, "Adios."