Question: What English composer had works premiered at Morley College and has no contemporary portrait?

Context paragraphs:
National Opera Studio: The National Opera Studio in London, England was established in 1977 by the Arts Council as a link between the music colleges and the six main UK opera companies.  It was resident at Morley College in Lambeth until 2003, when it gained use for the first time of its own dedicated premises in Chapel Yard, Wandsworth.  Its director is the soprano Kathryn Harries, who succeeded Donald Maxwell at the start of 2009, and its Head of Music is Mark Shanahan.  It is responsible for the training of approximately twelve singers each academic year, as well as three piano répétiteurs.  Its funding comes in part from the six main UK opera companies – Royal Opera House, English National Opera, Welsh National Opera, Scottish Opera, Opera North and the Glyndebourne Festival Opera.  Representatives from each company sit on the final audition panel for selection of each year's intake.  The nine-month course usually includes residencies at three of the national opera companies, as well as opera scenes performances in London throughout the year.

Morley College: Morley College is an adult education college in London.  It was founded in the 1880s and has a student population of 11,000 adult students.  It offers courses in a wide variety of fields including art and design, fashion, languages, drama, dance, music, health and humanities.

Yiorgos Magoulas: Yiorgos Magoulas, (Greek: Γιώργος Μαγουλάς) born in Athens in 1970, is an award winning Greek composer and guitarist.  He studied classical guitar, composition, arrangement and orchestration in Athens (National Conservatory of Athens) and London (Morley College of London).  In 1991, at the age of 21, he began his professional career by writing music for the "Research Theater- Dimitris Potamitis".  Since then, he has composed music for orchestra, theater, artistic events, films, television commercials, as well as music for about 150 documentaries.  He has released 3 CDs with instrumental music.  In 2000 his oratorio "Propitiation" was presented in London, following an assignment by the Church of England.  Since 2007 he has been the composer of the award winning documentary series entitled "War Zone" which was broadcast by the leading Greek TV network Mega Channel.

Morley College Choir: Morley College Choir was founded by Gustav Holst, during the period he was teaching music at Morley College.  The choir was led for many years by Michael Tippett, who conducted the ensemble for the first-ever recording of Thomas Tallis' Spem in Alium, and premiered a number of Tippett's works, including A Child of Our Time in March 1944.

Thomas Tallis: Thomas Tallis ( 1505 – 23 November 1585) was an English composer who occupies a primary place in anthologies of English choral music, and is considered one of England's greatest composers.  He is honoured for his original voice in English musicianship.  No contemporary portrait of Tallis survives: that painted by Gerard Vandergucht ("illustration"), dates from 150 years after Tallis died, and there is no reason to suppose that it is a likeness.  In a rare existing copy of his black letter signature, the composer spelled his last name "Tallys."

Ralph Heimans: Ralph Heimans, {'1': ", '2': ", '3': ", '4': "} , is an Australian-born contemporary portrait painter.  He is best known for his Diamond Jubilee Portrait of Her Majesty The Queen.

Edward Olive: Edward Olive (born 4 January 1970, in Dublin, Ireland) is a film and television actor.  He was a commercial litigation solicitor in London and Paris until pursuing his interests working as a professional screen actor in the UK, France and from 2002 based out of Madrid, Spain.  He studied drama in London at the City Literary Institute, Morley College and The Actor's Centre, as well as taking courses in the Royal Academy of Dramatic Art (RADA).  He also studied in Paris at Studio 34 and Coté Cour.  He has appeared in English, French and Spanish speaking roles.

Barry Till: He was born on 1 June 1923, educated at Harrow and served in the Coldstream Guards from 1942 to 1946.  He studied at Jesus College, Cambridge, where he read history and theology and in 1949 was awarded the Cambridge University Lightfoot Scholarship in ecclesiastical history with special commendation.  Thereafter, he studied at Westcott House, Cambridge, where his tutors included Alan Webster and Harry Williams, and contemporaries included Hugh Montefiore, all of whom remained great friends: he was ordained in 1951.  After a curacy in Bury, Lancashire he returned to his old college as Fellow, Chaplain and Tutor.  In 1960 he became Dean of Hong Kong, a post he held until 1964.  He was Principal of Morley College, London from 1965 to 1986 and Adviser (1973-1986), then Director (1986-1992) of the Baring Foundation.

Conjectural portrait: A conjectural portrait is a portrait made of a historical figure for whom no authentic contemporary portrait is available.  The depiction, then, may be variously informed by written accounts of physical appearance, conjecture based on the subject's culture and background, and/or the artist's conception of the subject's inner essence.

Pari intervallo: Pari intervallo is a composition by Estonian composer Arvo Pärt, written in 1976 in four parts without fixed instrumentation.  The composer later made versions for organ (1980), four recorders (1980), clarinet, trombone and string orchestra (1995), saxophone quartet (2002), two pianos or piano duet (2008), and eight or four cellos (2010).  "Pari intervallo" was one of seven works premiered in 1976 under the title tintinnabuli, the name of compositional style created by the composer.

Supporting paragraphs: Morley College Choir Thomas Tallis
Answer: Thomas Tallis