Parker's comments about Dankworth led to the engagement of the young British jazz musician for a short tour of Sweden, with the soprano-saxophonist Sidney Bechet.

In 1950, Dankworth formed a small group, the Dankworth Seven, as a vehicle for his writing activities as well as a showcase for several young jazz players, including himself (alto sax), Jimmy Deuchar (trumpet), Eddie Harvey (trombone), Don Rendell (tenor sax), Bill Le Sage (piano), Eric Dawson (bass) and Tony Kinsey (drums).

[13] The band performed at the Birdland jazz club in New York City, and shortly afterwards shared the stage with the Duke Ellington Orchestra for a number of concerts.

Dankworth's band also performed at a jazz event at New York's Lewisohn stadium where Louis Armstrong joined them for a set.

In 1959, Dankworth became chair of the Stars Campaign for Inter-Racial Friendship, set up to combat the fascist White Defence League.

[15] American altoist Cannonball Adderley sought and received Dankworth's permission to record the arrangement and had a minor hit in the US as a result.

[8] Some were full-time members of the Dankworth band at one time or another, like Tony Coe, Mike Gibbs, Peter King, Dudley Moore, George Tyndale, Daryl Runswick, John Taylor and Kenny Wheeler, while others such as Dave Holland, John McLaughlin, Tubby Hayes and Dick Morrissey were occasional participants.

[9] Among his best-known credits are the original themes for two British TV programmes, The Avengers (used from 1961 to 1964) and Tomorrow's World (included on the 1972 LP Lifeline).

He recorded an album of symphonic arrangements of many Ellington tunes featuring another Ellingtonian trumpet soloist Barry Lee Hall.

Other jazz musicians with whom Dankworth performed include George Shearing, Toots Thielemans, Benny Goodman, Herbie Hancock, Hank Jones, Slam Stewart and Oscar Peterson.

He always had an enthusiasm for jazz education, for many years running the Allmusic summer schools at the Stables in Wavendon near Milton Keynes, a theatre that Laine and he created in January 1970 in their back garden.

[21] In October 2009, at the end of a US tour with his wife, Dankworth was taken ill.[8] The couple cancelled a number of UK concert dates for the following month.

After her divorce from George Langridge became final, in 1957, a year later in 1958 Dankworth married jazz singer Cleo Laine in secret at Hampstead Registry Office.