Question: What type of music is this English composer who composed the music for "Blondel" best known for?

Context paragraphs:
Richard Addinsell: Richard Stewart Addinsell (13 January 190414 November 1977) was an English composer, best known for film music, primarily his "Warsaw Concerto", composed for the 1941 film "Dangerous Moonlight" (also known under the later title "Suicide Squadron").

Neil Richardson (composer): Neil Grant Richardson (5 February 1930 – 8 October 2010) was an English composer and conductor.  As a composer, he is perhaps best known for "Approaching Menace" (the "Mastermind" theme tune) and "The Riviera Affair".  During the 1960s–1990s, he was an arranger and conductor of various BBC Radio Orchestras, working on programmes such as "String Sound" and "The Radio Orchestra Show".  He was a prolific composer of library music for companies such as KPM, and his music has been used in numerous TV, film and radio productions.

Albert Ketèlbey: Albert William Ketèlbey ( ; born Ketelbey; 9 August 1875 – 26 November 1959) was an English composer, conductor and pianist, best known for his short pieces of light orchestral music.  He was born in Birmingham and moved to London in 1889 to study at Trinity College of Music.  After a brilliant studentship he did not pursue the classical career predicted for him, becoming musical director of the Vaudeville Theatre before gaining fame as a composer of light music and as a conductor of his own works.

Blondel (musical): Blondel, a rock opera musical by Tim Rice (book and lyrics) and Stephen Oliver (music), was inspired by, and very loosely based on, the life of the eponymous French troubadour.  The play is set during the period of the Third Crusade.

Stephen Oliver (composer): Stephen Michael Harding Oliver (10 March 1950 – 29 April 1992) was an English composer, best known for his operas.

Jane Joseph: Jane Marian Joseph (31 May 1894 – 9 March 1929) was an English composer, arranger and music teacher.  She was a pupil and later associate of the composer Gustav Holst, and was closely concerned in the organisation and management of various of the music festivals which Holst sponsored.  Many of her works were composed for performance at these festivals and similar occasions.  Her early death, which prevented the full realisation of her talents, was considered by her contemporaries as a considerable loss to English music.

Richard Arnell: Richard Anthony Sayer ("Tony") Arnell (15 September 191710 April 2009) was an English composer of classical music.  Arnell composed in all the established genres for the concert stage, and his list of works includes six completed symphonies (a seventh was realised by Martin Yates) and six string quartets.  At the Trinity College of Music, he "promoted a pioneering interest in film scores and electronic music" and jazz.  Electronic composer David Hewson, who worked with him on films including "Dilemma" (1981), "Doctor in the Sky" (1984), "Toulouse-Lautrec" (1986), and "The Light of the World" (1989), was one of his pupils.

Anne Dudley: Anne Dudley (born 7 May 1956) is an English composer, keyboardist, conductor and pop musician.  She was the first BBC Concert Orchestra's Composer in Association in 2001.  She has worked in both the classical and pop genres, but she is perhaps best known as one of the core members of the synthpop band Art of Noise and as a film composer.  In 1998 Dudley won an Academy Award for Best Original Musical or Comedy Score for "The Full Monty".  In addition to over twenty other film scores, in 2012 she served as music producer for the film version of "Les Misérables",

Thomas Morley: Thomas Morley (1557 or 1558 – early October 1602) was an English composer, theorist, singer and organist of the Renaissance.  He was one of the foremost members of the English Madrigal School.  He was also involved in music publishing, and from 1598 up to his death he held a printing patent (a type of monopoly).  He used the monopoly in partnership with professional music printers such as Thomas East.  According to Philip Brett and Tessa Murray, Morley was 'chiefly responsible for grafting the Italian shoot on to the native stock and initiating the curiously brief but brilliant flowering of the madrigal that constitutes one of the most colourful episodes in the history of English music'.

Nicholas Ludford: Nicholas Ludford (c. 1485 – c. 1557) was an English composer of the Tudor period.  He is known for his festal masses, which are preserved in two early-16th-century choirbooks, the Caius Choirbook at Caius College, Cambridge, and the Lambeth Choirbook at Lambeth Palace, London.  His surviving antiphons, all incomplete, are copied in the Peterhouse Partbooks (Henrican set).  Ludford is well-known as being the composer of the only surviving cycle of Lady Masses, small-scale settings of the Ordinary and Propers in three parts to be sung in the smaller chapels of religious institutions on each day of the week.  Ludford's composing career, which appears to have ended in 1535, is seen as bridging the gap between the music of Fayrfax and that of John Taverner (1495–1545).  Music scholar David Skinner has called Ludford "one of the last unsung geniuses of Tudor polyphony".  In his "Oxford History of English Music", John Caldwell observes of Ludford's six-part Mass and Magnificat "Benedicta" that it "is more a matter of astonishment that such mastery should be displayed by a composer of whom virtually nothing was known until modern times".

Supporting paragraphs: Blondel (musical) Stephen Oliver (composer)
Answer: operas.