Sir Lennox Randal Francis Berkeley (12 May 1903 – 26 December 1989) was an English composer.
He was born in Oxford, England, and educated at the Dragon School, Gresham's School and Merton College, Oxford. His father was Hastings George Fitzhardinge Berkeley, a captain in the Royal Navy and illegitimate son of George Lennox Rawdon Berkeley, 7th Earl of Berkeley (1827–1888).
In 1927, he went to Paris to study music with Nadia Boulanger, and there he became acquainted with Francis Poulenc, Igor Stravinsky, Darius Milhaud, Arthur Honegger and Albert Roussel. Berkeley also studied with Maurice Ravel, often cited as a key influence in Berkeley's technical development as a composer.
In 1936 he met Benjamin Britten, another old boy of Gresham's School, at the ISCM Festival in Barcelona. Berkeley fell in love with Britten, who appears to have been wary of entering a relationship, writing in his diary, "we have come to an agreement on that subject." Nevertheless, the two composers shared a house for a year, living in the Old Mill at Snape, Suffolk, which Britten had acquired in July 1937. They subsequently enjoyed a long friendship and artistic association, collaborating on a number of works; these included the suite of Catalan dances titled Mont Juic, and Variations on an Elizabethan Theme (the latter also with four other composers).
He wrote several piano works for the pianist Colin Horsley, who commissioned the Horn Trio and some piano pieces, and gave the first performances and/or made the premier recordings of a number of his works, including his third Piano Concerto (1958).
He was Professor of Composition in the Royal Academy of Music from 1946 to 1968 and his pupils included Richard Rodney Bennett, David Bedford, Clive Strutt and John Tavener. 1954 saw the premiere of his first opera, Nelson, at Sadler's Wells. He was knighted in 1974 and from 1977–83 was President of the Cheltenham Festival.
- 1983 : Member of the Royal Academy of Science, Letters and Fine Arts of Belgium. 
Berkeley's earlier music is broadly tonal, influenced by the neoclassical music of Stravinsky. Berkeley's contact and friendship with composers such as Ravel and Poulenc and his studies in Paris with Boulanger lend his music a 'French' quality, demonstrated by its "emphasis on melody, the lucid textures and a conciseness of expression". He maintained a negative view of atonal music at least up until 1948, when he wrote:
I have never been able to derive much satisfaction from atonal music. The absence of key makes modulation an impossibility, and this, to my mind, causes monotony [...] I am not, of course, in favour of rigidly adhering to the old key-system, but some sort of tonal centre seems to me a necessity.
However, from the mid-1950s, Berkeley apparently felt a need to revise his style of composition, later telling the Canadian composer, R. Murray Schafer that "it's natural for a composer to feel a need to enlarge his idiom." He started including tone rows and aspects of serial technique in his compositions around the time of the Concertino, op. 49 (1955) and the opera Ruth (1955-6). His shift in opinion was demonstrated in an interview with The Times in 1959:
I'm not opposed to serial music; I've benefited from studying it, and I have sometimes found myself writing serial themes - although I don't elaborate on them according to strict serial principles, because I'm quite definitely a tonal composer. And there are some exceptions to the gospel of intellectualisation - I enjoyed listening to the record of Boulez's Le marteau sans maître very much, because there the timbres of the music were attractive in themselves.
His disciples included avantgarde composers such as Brian Ferneyhough, who felt that he learned nothing from him because of the gap between their musical conceptions, remembering him as "a notably urbane and well-meaning presence" but whose "Nadia Boulenger influenced gallic aesthetics were completely unable to deal with my compositional needs."
- Nelson, (1951)
- A Dinner Engagement, Op. 45 (1954)
- Ruth, Op. 50 (1955–6)
- Castaway, Op. 68 (1967)
- Faldon Park, (1979–85). Incomplete.
- Mont Juic, suite of Catalan dances, Op. 9 (written jointly with Benjamin Britten)
- Serenade, for string orchestra (1938–9)
- Symphony No. 1 (1936–40)
- Divertimento (1943)
- Piano Concerto in B-flat major, Op. 29 (1947–8)
- Concerto for Two Pianos and Orchestra, Op. 30 (1948)
- Symphony No. 2 (1958, revised 1976)
- Symphony No. 3, in one movement (1968–9)
- Sinfonia Concertante, for oboe and chamber orchestra (1972–3)
- Voices of the Night, Op. 86 (1973)
- Guitar Concerto, Op. 88
- Symphony No. 4 (1977–8)
- A Festival Anthem, Op. 21, No. 2 (1945)
- Crux fidelis, Op. 43, No. 1 (1955)
- I sing of a maiden (1966)
- Look up, sweet babe, Op. 43, No. 2 (1955)
- Missa Brevis, Op. 57 (1960)
- Mass for five voices, Op. 64 (1964)
- Three Latin Motets, Op. 83, No. 1 (1972)
- The Lord is my shepherd, Op. 91, No. 1 (1975)
- Magnificat and Nunc dimittis, Op. 99 (1980)
- Four Poems of St Teresa of Ávila, Op. 27, for contralto and string orchestra (1947)
- Three Greek Songs, Op. 38 (1953)
- Five Poems by W. H. Auden, Op. 53
- String Quartet No. 1, Op. 6 (1935)
- String Quartet No. 2, Op. 15 (1941)
- String Trio, Op. 19 (1943)
- Sonata in D minor for viola and piano, Op. 22 (1945)
- Introduction and Allegro, for solo violin (1949) (edited by Ivry Gitlis)
- Trio for horn, violin and piano, Op. 44 (1952)
- Sextet for clarinet, horn and string quartet, Op. 47 (1954)
- String Quartet No. 3, Op. 76 (1970)
- Introduction and Allegro, for double bass and piano (1972) (for Rodney Slatford)
- Duo for cello and piano
- Sonata Op. 97 for flute and piano
- Sonatina Op. 13 for recorder and piano
- Three Pieces for Solo Viola, WoO (Dedicated to Stephan Deák, discovered 2004.) 
- Three Pieces, Op. 2 (1935)
- Piano Sonata in A major, Op. 20 (1941–5)
- Six Preludes, Op. 23 (1945)
- Three Mazurkas, Op. 31 No. 1 (1939–49)
- Quatre pièces pour la guitare (1928)
- Sonatina, Op. 52, No. 1 (1957)
- Theme and Variations, Op. 77 (1970)
- Three Pieces for Clarinet, (1939)
- Sonatina for Flute or Treble Recorder and Piano (1940)
- Theme and Variations (1950)
- A Dinner Engagement – Chandos CHAN10219
- Missa Brevis – Naxos 8.557277
- Serenade for Strings – Chandos CHAN 9981
- Chamber Works for Wind, Strings & Piano - Regis RRC1380
- Levens, R.G.C., ed. (1964). Merton College Register 1900-1964. Oxford: Basil Blackwell. p. 149.
- Oliver, Michael (1996). Benjamin Britten. University of Michigan: Phaidon. p. 60. ISBN 9780714832777.
- Evans, John (2010). Journeying Boy: The Diaries of the Young Benjamin Britten 1928-1938. Faber and Faber. p. 366. ISBN 9780571274642.
- Evans, John (2010). Journeying Boy: The Diaries of the Young Benjamin Britten 1928-1938. Faber and Faber. p. 494. ISBN 9780571274642.
- Peter Dickinson The Music of Lennox Berkeley – Page 77 2003 "Colin Horsley remembered Berkeley's time at the BBC because he was reputed to have kept manuscript paper under his desk and was obviously longing to get more time to compose. Since it was there that he met his wife it is no wonder ..."
- Scotland, Tony. "Lennox Berkeley and his Music (biography)". Retrieved 7 October 2014.
- Death notice, The Times, London, 25 February 2016, p.61
- Musical leader 1958 Page 21 "Lennox Berkeley launched his Third Piano Concerto with Colin Horsley, for whom the work was written, at the Royal Philharmonic Society's Festival Hall series recently"
- "Historical plaques about Lennox Berkeley". Open Plaques. Retrieved 29 September 2015.
- "Lennox Berkeley timeline". The Lennox Berkeley Society. Retrieved 29 September 2015.
- Index biographique des membres et associés de l'Académie royale de Belgique (1769-2005)
- Stevens, Douglas (2011). Lennox Berkeley : a critical study of his music (Ph.D.). University of Bristol.
- Rushton, James. "Lennox Berkeley - Five Short Pieces (1936)". Music Sales Classical. Retrieved 29 September 2015.
- Dickinson, Peter (2003). The music of Lennox Berkeley (2nd ed.). Woodbridge: The Boydell Press. p. 161. ISBN 9780851159362.
- Dickinson, Peter (2012). Lennox Berkeley and friends : writings, letters and interviews. Woodbridge: Boydell Press. p. 9. ISBN 9781843837855.
- Dickinson, ed. Peter (2012). Lennox Berkeley and friends : writings, letters and interviews. Woodbridge: Boydell Press. p. 110. ISBN 9781843837855.CS1 maint: extra text: authors list (link)
- Brian Ferneyhough - An interview with the English composer/professor who now resides in California. "I am always actively thinking of current activities.". Musicguy 247
- "Introduction and Allegro for Solo Violin." 21 April 2018. Retrieved 21 April 2018 – via Open WorldCat.
- Review Sextet May 2008, quote: Berkeley wrote his three movement Sextet for Clarinet, Horn and String Quartet, Op. 47 in 1954 for the Melos Ensemble.
- Daly, Thomas. "Works by Sir Lennox Berkeley (complete listing) (containing the keyword '13')". www.lennoxberkeley.org.uk. Retrieved 21 April 2018.
- Scotland, Tony; Raphael, Terroni. "Three Pieces for Solo Viola". Lennox Berkeley Society. Retrieved 20 October 2018.