Bernard Stanley Bilk was born in the Somerset village of Pensford on January 28, 1929. The name Acker is West Country slang for a friend or mate, and it stuck from boyhood. His parents tried him on the piano, but he preferred the outdoors, and two accidents left marks that he later said shaped his clarinet sound: he lost two front teeth in a school fight and half a finger in a sledging accident. After school he spent three years in the W.D. & H.O. Wills cigarette factory in Bristol, then three years of National Service with the Royal Engineers in the Suez Canal Zone. There a fellow sapper handed him a clarinet bought at a bazaar, with no reed. Bilk learned by copying records, formed a soldiers' band that he remembered as the Original Egyptian Stompers, and kept an army-issue instrument when he was demobilised. Back in Somerset he qualified as a blacksmith in his uncle's business and played in Bristol's jazz clubs at night, including the Crown and Dove pub on Rupert Street.

His first professional step was a spell in London in Ken Colyer's band, the New Orleans revivalist group that stood for the strict wing of British traditional jazz; he was with it from 1954 to 1956, and a Lake reissue of Colyer's Jazzmen recordings credits him on clarinet. Bilk disliked London, went back to the West Country and started his own group, first the Chew Valley Jazzmen in Pensford and then the Bristol Paramount Jazz Band. The band's agent booked it into a beer bar in Düsseldorf, Germany, for seven hours a night, seven nights a week. That grind tightened the ensemble, and the look that became his trademark, a bowler hat, goatee and striped waistcoat, took shape in the same period. An early single, "Dippermouth Blues," the King Oliver piece, came out on Tempo in 1956.

The trad boom of the late 1950s carried Mr. Acker Bilk and His Paramount Jazz Band from clubs to the charts. "Summer Set," a pun on the home county, written by Bilk with the pianist Dave Collett, reached No. 5 in the UK in 1960 and began a run of eleven chart singles that included "Buona Sera" and "That's My Home," both No. 7. The band appeared at the Royal Variety Performance in 1961, and the album The Seven Ages of Acker (Columbia, 1960) reached No. 6 on the UK chart. With the trombonist Chris Barber and the trumpeter Kenny Ball he was one of the three leading names of the boom: The Best of Ball, Barber and Bilk reached No. 1 on the UK album chart in 1962, and the three later toured together as "The 3Bs."

What reached beyond the boom was a piece for his young daughter. Bilk wrote a clarinet melody called "Jenny," and when the BBC chose it as the theme for a children's serial titled Stranger on the Shore, it took the serial's name. The producer Denis Preston had persuaded him to record it with strings, and the arranger Leon Young wrote the setting for the Leon Young String Chorale, built around Bilk's low, breathy, quavering clarinet. It was recorded at Lansdowne Studios with the engineer Adrian Kerridge and released by Columbia in October 1961 (DB 4750, with "Take My Lips" on the other side). An appearance as the subject of the television programme This Is Your Life helped it stay on the UK chart for 55 weeks. It topped the New Musical Express and Record Mirror charts at the start of January 1962, peaked at No. 2 on the Record Retailer chart and became the UK's best-selling single of 1962. In the United States it was issued on Atlantic's Atco label and on May 26, 1962 became the first British recording to reach No. 1 on the Billboard Hot 100. Billboard named it the top single of 1962, and it spent seven weeks at No. 1 on the Easy Listening chart. It had sold 1.16 million copies in the UK by 2012 and is counted as the best-selling instrumental single of all time. The 1962 album Stranger on the Shore reached No. 6 in the UK and No. 3 in the US. Bilk and the band also appeared as themselves in two 1962 British films, Richard Lester's It's Trad, Dad! (released in the US as Ring-a-Ding Rhythm) and the comedy Band of Thieves. In May 1969 the tune orbited the Moon with the Apollo 10 crew, on a cassette that Gene Cernan brought along.

The Beatles-era shift in British taste ended the string of hits. "A Taste of Honey" reached No. 16 in 1963, and Bilk moved toward cabaret and Europe while still recording. Atco issued three of his mid-1960s albums in the US, among them Together (1965) with the Danish pianist Bent Fabric, best known for "Alley Cat." The most jazz-minded record of the decade came in 1968: Blue Acker (Columbia TWO 230), made with the Stan Tracey Big Brass under Denis Preston's supervision, with arrangements by the pianist Stan Tracey, who stood on the modern side of British jazz. Its eight tracks mix standards of the trad repertoire, "Royal Garden Blues," "Tin Roof Blues" and "Mood Indigo," with Duke Ellington's "Festival Junction" and three Tracey originals. The writer Duncan Heining counts the album among the highlights of British jazz of its period. A year later he sat in on one track, Ellington's "Creole Love Call," on Tracey's big-band tribute album We Love You Madly (Columbia SX 6320, 1969). Bilk had one more big hit in 1976 with "Aria," which reached No. 5 in the UK, played the interval spot at the Eurovision Song Contest in May 1977, and made his last chart appearance in 1978 with the television-promoted album Evergreen (No. 17).

He kept the Paramount Jazz Band working for the rest of his life, in changing lineups, and the jazz side of his discography kept growing. In 1985 he made Together Again with Ken Colyer's Jazzmen, and in 1992 and 1994 he co-led two CDs with the trumpeter Humphrey Lyttelton, At Sundown and Three in the Morning. He shared records with Chris Barber and Kenny Ball for decades, made the 2002 CD Azure with the cartoonist and clarinetist Wally Fawkes, and played clarinet on two Van Morrison albums, Down the Road (2002) and What's Wrong with This Picture? (2003), co-writing a song on each. He was appointed MBE in 2001 and received the Gold Award at the 2005 BBC Jazz Awards. A throat cancer diagnosed in 1997 was treated with surgery and radiation, and he later had further cancer treatment and a minor stroke. He played the Brecon Jazz Festival in 2013. In 2012, after fifty years, he admitted to being fed up with playing his signature tune, though he had long called it his old-age pension. He married his childhood sweetheart Jean Hawkins in 1954, and they had two children, Jenny and Pete. He painted the Somerset countryside as a hobby, and he passed away in Bath on November 2, 2014, at the age of 85.

Bilk played trad jazz in the early New Orleans manner: a front line of clarinet, trumpet and trombone over banjo, piano, bass and drums, with no amplification and, apart from a spell with the saxophonist Bruce Turner, no saxophones. His own voice on the instrument sat in the low register, with a wide, breathy vibrato and a slow, singing line that AllMusic describes as heavily quavering. AllMusic files him under trad jazz, and a reviewer of his 1962 Beau Jazz sessions praised his mellow tone and added that purists who complained about the band's costumes and commercial success were overlooking how good the music was. He also sang, in a plain, friendly style, on numbers such as "That's My Home" and "The Folks Who Live on the Hill."

His career ran for two audiences, and the divide is stated plainly here. The band's records of New Orleans repertoire, from "Dippermouth Blues," the 1923 King Oliver recording that also featured Louis Armstrong, to "Petite Fleur," the clarinet piece by Sidney Bechet that he recorded as a single in 1966, were played straight, and he returned to Bechet with "Bagatelle" on the 1971 album Horn of Plenty. The records that made him famous worldwide, led by "Stranger on the Shore," were string-backed easy-listening instrumentals that topped the pop and easy listening charts. Both lines ran in parallel for the rest of his career, and the clarinet sound stayed the same in each. The apprenticeship with Ken Colyer, the long run of the Paramount Jazz Band, the Stan Tracey collaboration, the BBC Jazz Award and the invitations from Van Morrison are the evidence that jazz musicians treated him as one of their own.