Andy Williams, the effortlessly smooth crooner best known for his rendition of “Moon River,” died on Tuesday night in his Branson, Mo., home after suffering from bladder cancer. He was 84.

Maintaining a 75-year career in show business, Williams transitioned from child singer to heartthrob crooner, TV show host, kudocast mainstay and finally a local institution in his adopted home of Branson. Possessing an innate sense of classy cool that stayed with him long after his music ceased to be fashionable, Williams also recorded the definitive versions of “Can’t Get Used to Losing You” and “Happy Heart.”

Though he spent the last stretch of his career performing far away from the coastal showbiz capitals, Williams was a consummate entertainment industry creature, frequently performing at the Academy Awards and hosting the Grammys for seven straight years. His interpretations of songs from films are among his best-known — in addition to his signature “Moon River,” he also had a hit with the fellow Mancini-Mercer tune “Days of Wine and Roses” as well as the theme to “Love Story.” He accumulated a total of three platinum records and 18 gold throughout his career.

Born in the tiny town of Wall Lake, Iowa, Williams was the youngest of three brothers with whom he formed the Williams Brothers Quartet when he was 8. Managed by their father, the boys gradually gained traction performing on regional radio, attracting the attention of Bing Crosby, who featured the young singers on his 1944 hit “Swinging on a Star.”

After bouncing around Hollywood for several years — with Williams even dubbing Lauren Bacall’s singing voice for “To Have and Have Not,” though his recording was cut before its release — the quartet joined up with “Eloise” author Kay Thompson to form a nightclub act, which became a hot nationwide touring draw for the rest of the decade.

The quartet split up in 1951, and Williams pursued a solo career in New York, at one point succumbing to poverty as his initial singles for Label X faltered. His fortunes improved thanks to television, when NBC’s “Tonight Show with Steve Allen” booked him. Williams was perfectly suited to the new medium, with his clean-cut good looks and genial demeanor, and he would become a regular on the show for a solid two-year period.

A contract with Cadence Records followed, and Williams landed his first top-10 hit in 1956 with “Canadian Sunset.” Though Williams’ style was more in line with that of Frank Sinatra and Perry Como, many of these earlier recordings saw his handlers attempt to conform him to the Elvis Presley model, at times with odd results. Nonetheless, 1957’s Presley-styled “Butterfly” was his first and only No. 1 hit, and follow-ups “I Like Your Kind of Love” and “Are You Sincere” also charted well.

Signing to Columbia Records in 1962, Williams began to hew more firmly to his “natural style” with 1963’s “Can’t Get Used to Losing You,” which hit No. 2 on both the U.S. and U.K. charts. Suggested by Henry Mancini to sing “Moon River” — sung by Audrey Hepburn in “Breakfast at Tiffany’s” — at the Oscars in 1962, Williams happened upon his signature song, though his recording was never released as a single.

It was, however, included on that year’s film-centric LP “Moon River and Other Great Movie Themes,” which reached No. 3 on the album chart; 1963 follow-up LP “Days of Wine and Roses and Other TV Requests” was an even bigger smash, topping the album chart for 16 consecutive weeks.

Also in 1962, Williams bowed his own variety show, “The Andy Williams Show,” on NBC. The skein ran until 1971, and in addition to cementing Williams’ popularity and winning him two Emmys, it also introduced audiences to the Osmond Brothers and Elton John. He also started his own label, Barnaby Records, on which he reissued his own Cadence material, as well as music from the Everly Brothers, Ray Stevens and the earliest recordings from the then-unknown Jimmy Buffett.

Unlike most of his crooner contemporaries, Williams continued to chart into the 1970s, reaching No. 9 on the singles chart in 1970 with “Where Do I Begin? (Love Story),” the theme to the Arthur Hiller-directed B.O. smash. Although his weekly show had been mothballed, Williams was a continuous TV presence throughout the decade, whether hosting the Grammys and his annual Christmas specials — two of his yuletide albums went platinum — or singing the national anthem at the 1973 Super Bowl.

Though a self-described lifelong Republican, Williams was nonetheless an enthusiastic supporter of Robert Kennedy’s 1968 presidential campaign, and sang “The Battle Hymn of the Republic” at his funeral. He also admitted to experimenting with LSD, and he spoke out against the Nixon administration’s attempt to deport John Lennon.

His otherwise aboveboard image was briefly touched by scandal in the late-1970s, when his ex-wife Claudine Longet, to whom he was married from 1961-75, was arrested for the fatal shooting of her professional skier boyfriend, Spider Sabich. Williams testified on her behalf at trial, accompanied her to the courtroom and continued to maintain her innocence after she was controversially convicted of a misdemeanor criminal negligence charge.

Eventually growing weary of touring, Williams relocated to the Midwestern entertainment hub of Branson, where he staged a third act as the city’s most enduring draw. At the time the only non-country musician among the resident acts, he opened the $12 million Andy Williams Moon River Theater in 1992. There he performed a blistering schedule of two performances per day, six days per week, for nine months out of the year. Only in later years was he forced to slow this pace, limiting himself to one performance a day, though retirement was never in his plans. As he told the AP in 2001, “I’ll keep going until I get to the point where I can’t get out onstage.”

Williams is survived by his wife Debbie, to whom he was married for 26 years, and three children.

(The Associated Press contributed to this report.)