Born in Oklahoma, B.J. had a breakthrough in his music career in 1966, when his cover of Hank Williams' 1949 track 'I'm So Lonesome I Could Cry' became a top 10 hit on the Billboard Hot 100. He'd follow that up with 1968's 'Hooked on a Feeling'.
The track actually won him an Oscar for Best Original Song in 1969 for 'Butch Cassidy and the Sundance Kid'.
However, Robert Redford - who starred in the movie - previously admitted he initially questioned whether the song truly belonged in the film.
He said in 2019: "When the film was released, I was highly critical - how did the song fit with the film? There was no rain.
"At the time, it seemed like a dumb idea. How wrong I was."
A year later, his cover of Burt Bacharach and Hal David's 'Raindrops Keep Fallin' On My Head' soundtracked 'Butch Cassidy and the Sundance Kid' and won the Oscar for Best Song,
“I just wanted to take this unique opportunity to share my gratitude to Gloria, my wonderful wife and my rock for over 53 years, my family, friends, and fans,” Thomas said through his publicist.
“I’m so blessed to have had the opportunity to record and perform beautiful songs in pop, country, and gospel music, and to share those wonderful songs and memories around the world with millions of you. I ask all of you for your prayers during this time and that my music can live on with you.”
Deadline reports that the 78-year-old star is undergoing treatment at a facility in Texas.
