Country star Glen Campbell's life story is about to be turned into a new movie by the man who produced Johnny Cash biopic Walk the Line.

Moviemaker James Keach has just signed on to develop a film based on the Wichita Lineman singer's amazing story, spanning six decades.

Campbell's story began as a talented studio guitarist and part-time Beach Boys star, through his heyday as a music and TV superstar, to his drink and drug woes and his current battle with Alzheimer's disease.

He and Cash had similarities in their careers, both fronting TV shows and seeing their appeal widen across genres.

Campbell has recently embarked on what he says will be his final tour and released what may be his last album, Ghost on the Canvas.