As a child Ottis Dewey Whitman jnr, who was born in Tampa, Florida, liked to listen to Jimmie Rodgers yodel on the family radio.
After leaving high school he worked at a meatpacking plant and later joined the US navy, where he served in the South Pacific and entertained shipmates by singing, yodelling and playing guitar, which he had learned to play upside down and left-handed.
After the war he played on local radio stations. "Colonel" Tom Parker, who later managed Elvis Presley, heard him and helped him get a contract with RCA Victor Records.
Whitman adopted the stage name Slim and began to appear on the radio show Louisiana Hayride, whose performers also included Hank Williams, Johnny Cash and Jerry Lee Lewis.
In 1952 he had his first hit song, Love Song of the Waterfall, which 25 years later became part of the soundtrack for Close Encounters of the Third Kind. He nonetheless kept his day job as a postman.
His next success, Indian Love Call, came from a 1924 operetta and had previously been recorded by Nelson Eddy and Jeanette MacDonald. Whitman's version not only reached No 2 in the country charts, but also appeared in the pop top 10.
The director Tim Burton paid it a sort of tribute in his film Mars Attacks! (1996), in which Whitman's recording is used as a weapon against alien invaders. "Yes," said Whitman with satisfaction in a 2008 interview, "I'm the one who killed the blasted Martians."
Popular
He gave up his job as a postman and in 1954 he recorded Rose Marie, which raced to the top of the charts. His longtime popularity in Britain and Ireland began when a promoter arranged to have the song broadcast on Radio Luxembourg. Not until 1992 was the song's long reign at the top of the charts surpassed, by Bryan Adams's (Everything I Do) I Do It for You.
In 1956, he became the first American country artist to play the London Palladium.
His other hits included Have I Told You Lately That I Love You?, Red River Valley, Danny Boy and I'll Take You Home Again, Kathleen. He was inducted in the Country Music Hall of Fame and given a star on the Hollywood Walk of Fame. His wife of 67 years died in 2009.
Whitman, the country crooner with the weather-beaten face, velvet voice and sentimental lyrics, was often the object of humour, almost always good-natured. In the early 1980s a disc jockey offered Slim Whitman makeup kits “complete with receding hairline, furry black eyebrows and a cream to make your upper lip quiver”.
In 1997 Rush Limbaugh whimsically suggested that when Whitman's songs were played backward, the devil's voice could be heard.
Favourite
Michael Jackson named him one of his 10 favourite vocalists. George Harrison credited him as an early influence. Paul McCartney said Whitman gave him the idea of playing the guitar left-handed.
Elvis Presley, in his first professional appearance in Memphis in 1954, opened for Whitman. Mistakenly billed as Ellis, he was paid $50; Whitman got $500. Whitman later let Presley borrow his trademark white rhinestone jacket.
Through an eclectic repertory that included Broadway show tunes, European folk music, religious songs, cowboy songs and, of course, love songs, he said he strove to reach everyday people, to bring “the big songs down to the people’s size”.
His early fame was eclipsed by the rise of rock ’n’ roll. Throughout the 1960s and 1970s he concentrated on performing for his overseas audiences, returning to semi-retirement in Middleburg, Florida.
He told Associated Press in 1991 that he wanted to be thought of as “a nice guy” and a good father. “I’d like people to remember me,” he said, “as having a good voice and a clean suit.”
He is survived by his daughter, Sharon Beagle; his son, Byron; two grandchildren; and two great-grandchildren.