Glen Campbell, the country music star who produced 75 chart hits including "Rhinestone Cowboy" and "By the Time I Get to Phoenix" has died at age 81, his family have announced.

Campbell was one of the best known voices in country music, who became one of the biggest stars of the 1960s and 70s and also branched out into TV and film roles.

He had died in Nashville on Tuesday after a "long and courageous battle with Alzheimer's disease", his family said in a statement posted on his website.

Campbell was the youngest of 12 children in a desperately poor sharecropping family in Arkansas, whose birth in 1936 came as the US was gripped by a deep economic depression.

He got his first guitar at age four and quickly showed a talent for music that would define his life.

Campbell first made his name working in The Wrecking Crew group of studio musicians who worked under legendary producer Phil Spector.

He contributed to a host of famed records including the Byrds' Mr. Tambourine Man, and the Beach Boys album Pet Sounds.

That contact led to an invite to join the Beach Boys on tour in 1964 to replace Brian Wilson after his nervous breakdown.

Meanwhile Campbell was also developing his career as a solo artist, winning his first record deal in 1962 and scoring his first major hit five years later with "By the Time I Get to Phoenix".

It was just the start of a career that saw him rise to become one of the biggest musical stars of the late 1960s and 1970s. He sold more than 45 million records, had 12 gold albums and 75 chart hits.

Campbell also branched out in TV and film, presenting the television show "The Glen Campbell Good Time Hour" between 1969 and 1972, which was screened in the UK, Australia and Singapore and featured some of the biggest music stars of the day.

He also co-starred with John Wayne in the 1969 movie "True Grit" - one of more than ten feature film roles he took on.

In 2011, Campbell, announced that he had been diagnosed with Alzheimer's disease and would be retiring from his music career.

He launched a final tour before spending his final years in a care home.

He is survived by his wife, Kim Campbell of Nashville, TN; their three children, Cal, Shannon and Ashley.

He also leaves five children from previous marriages, Debby, Kelli, Travis, Kane, and Dillon; ten grandchildren, with a line stretching into great-great-grandchildren.

Fans have been paying tribute on social media.