NASHVILLE (CBSDFW.COM) – Glen Campbell, the voice behind several Top 40 hits including “By the Time I Get to Phoenix,” “Rhinestone Cowboy” and “Wichita Lineman” died Tuesday. He was 81.

Campbell’s family said the singer died Tuesday morning in Nashville. No cause of death was immediately given. Campbell announced in June 2011 that he had been diagnosed with Alzheimer’s disease and that it was in the early stages at that time.

Campbell was considered country’s first crossover star, but he told Anthony Mason on CBS’ “Sunday Morning” that he never thought of himself as a country singer.

“No, I’m a singer, and I really like good songs,” he said.

Campbell was a massive star in the late 1960s and 1970s. He sold more than 45 million records and has 12 gold albums and 75 chart hits. He was a six-time Grammy award winner.

Campbell was married four times and had eight children.

In April of this year, Campbell’s daughter Ashley wrote a song about her father’s battle with the Alzheimers and performed it on an episode “Country’s Family Reunion Kickin Back” series.

Campbell’s family posted the following tribute to his web page.

It is with the heaviest of hearts that we announce the passing of our beloved husband, father, grandfather, and legendary singer and guitarist, Glen Travis Campbell, at the age of 81, following his long and courageous battle with Alzheimer’s disease.

Glen is survived by his wife, Kim Campbell of Nashville, TN; their three children, Cal, Shannon and Ashley; his children from previous marriages, Debby, Kelli, Travis, Kane, and Dillon; ten grandchildren, great- and great-great-grandchildren; sisters Barbara, Sandra, and Jane; and brothers John Wallace “Shorty” and Gerald.

In lieu of flowers, donations can be made to the Glen Campbell Memorial Fund at BrightFocus Foundation through the donation page.

Ashley echoed her family’s grief in a tweet sent out Tuesday afternoon.

Fort Worth’s Bass Hall tweeted their own tribute to the singer who had graced their stage in the past. “We’re honored #GlenCampbell graced our stage.”

In Nashville, the Grand Ole Opry tweeted, “Our hearts are heavy by the passing of country music icon@GlenCampbell. Our thoughts and prayers are with the Campbell Family.”