George Jones, a classic country singer with a voice full of raw honky-tonk emotion and a life full of honky-tonk turmoil, died on Friday at age 81, his spokesman said.

Jones, whose career spanned more than six decades and included hits such as "He Stopped Loving Her Today" and "Window Up Above" died at Vanderbilt University Medical Center, in Nashville.

He had been hospitalized since April 18 with fever and irregular blood pressure, spokesman Kirt Webster said. In November 2012, Jones embarked on a farewell tour after a career that produced his first top 10 record in 1955 with "Why Baby Why."

The "Grand Tour" was to conclude in Nashville in November this year, where Jones was to be joined by some of the many stars who influenced him.

News of his death brought tributes from a number of country music's top stars.

"Heaven better get ready for George Jones. He will always be the greatest singer of real country music - there'll never be another," Alan Jackson said on Twitter. Dolly Parton said, "My heart is absolutely broken. George Jones was my all time favorite singer and one of my favorite people in the world."

Like his idol, Hank Williams, Jones battled addiction. Alcohol and cocaine frequently derailed his career and at one point his reputation for canceling performances earned him the nickname No-Show Jones.

But when Jones did show up and was in good form, listeners were treated to a powerful and evocative voice. As his late contemporary Waylon Jennings put it, "If we could all sound like we wanted to, then we'd all sound like George Jones."