Are both Giacomo Puccini and Peter Maxwell Davies considered composers?
yes
Giacomo Puccini
Giacomo Antonio Domenico Michele Secondo Maria Puccini (] ; 22 December 1858 29 November 1924) was an Italian opera composer who has been called "the greatest composer of Italian opera after Verdi".
Peter Maxwell Davies
Sir Peter Maxwell Davies (8 September 1934 – 14 March 2016) was an English composer and conductor.
 In 2004 he was made Master of the Queen's Music.
Bethany Beardslee
Bethany Beardslee (born December 25, 1925) is an American soprano particularly noted for her collaborations with major 20th-century composers, such as Igor Stravinsky, Milton Babbitt, Pierre Boulez, George Perle, Sir Peter Maxwell Davies and her performances of great contemporary classical music by Arnold Schoenberg, Alban Berg, Anton Webern.
 Her legacy amongst midcentury composers was as a "composer's singer"—for her commitment to the highest art of new music.
 Milton Babbitt said of her "She manages to learn music no one else in the world can.
 She can work, work, work."
 In a 1961 interview for Newsweek, Beardslee flaunted her unflinching repertoire and disdain for commercialism: "I don't think in terms of the public... Music is for the musicians.
 If the public wants to come along and study it, fine.
 I don't go and try to tell a scientist his business because I don't know anything about it.
 Music is just the same way.
 Music is "not" entertainment." Rohan Kriwaczek
Rohan Kriwaczek is a British writer, composer and violinist of part-Austrian descent.
 He studied under Peter Maxwell Davies, Oliver Knussen and Judith Weir, and is a prolific creator of classical works, scores for theatre, TV, and radio, he has become best known as "England's foremost authority on the history and practice of Funerary Violin", a musical art form he invented, complete with a history and composers dating back several centuries.
 He is the author of the 2006 book "An Incomplete History of the Art of Funerary Violin" that purports to document this musical genre and contains numerous musical examples in score. Neil Mackie
Neil Mackie (born 1946) is a Scottish tenor.
 During his career as a singer, he was associated with the works of 20th-century composers, particularly Benjamin Britten, and Peter Maxwell Davies.
 He created the title role in Davies's opera "The Martyrdom of St Magnus" and Sandy in his "The Lighthouse" and performed in the world premieres of Davies's "Into the Labyrinth", cantata for tenor and chamber orchestra, and "The Jacobite Rising".
 He has also premiered vocal works by Elliott Carter ("In Sleep, in Thunder"), Hans Werner Henze ("Three Auden Songs") and songs by Benjamin Britten. New Music Manchester
New Music Manchester refers to a group of English composers and performers who studied at the Royal Manchester College of Music (now the RNCM) and Manchester University in the 1950s.
 The Manchester School is principally identified with the composers Harrison Birtwistle, Peter Maxwell Davies and Alexander Goehr, and together with the pianist John Ogdon and the conductor and trumpeter Elgar Howarth they formed the group New Music Manchester.
 Its members played a significant role in reshaping the landscape of British music in the later 20th century. Requiem (Henze)
Hans Werner Henze composed the nine Sacred Concertos that comprise his Requiem over the course of three years from 1991 to 1993 on commissions from the London Sinfonietta, Suntory Corporation for the NHK Philharmonic, and Westdeutscher Rundfunk, Cologne.
 The first movement, "Introitus: Requiem Aeternam" was commissioned by the London Sinfonietta as part of a memorial concert for Artistic Director Michael Vyner who died on 20 October 1989.
 In addition to Henze, the London Sinfonietta also commissioned seven other prominent composers (Luciano Berio, Sir Harrison Birtwistle, Sir Peter Maxwell Davies, Toru Takemitsu, Oliver Knussen, and Nigel Osborne) to write works in Vyner's memory to make up the program which was performed on the 6 May 1990. Taverner (opera)
Taverner is an opera with music and libretto by Peter Maxwell Davies.
 It is based on the life of the 16th-century English composer John Taverner, but in what Davies himself acknowledged was a non-realistic treatment.
 The gestation for the opera dated as far back as 1956 during Davies's years in Manchester, and continued when he went to Princeton University in 1962.
 Davies produced several instrumental works related to the opera during this gestation period, including the "Points and Dances from 'Taverner and the "Second Fantasia on John Taverner's "In Nomine"".
 Davies had completed the opera in 1968, but lost parts of the score in a fire at his Dorset cottage in 1969, which necessitated recomposition. Urbain Grandier
Urbain Grandier (born in 1590 in Bouère, died in Mayenne – 18 August 1634 in Loudun) was a French Catholic priest who was burned at the stake after being convicted of witchcraft, following the events of the so-called "Loudun Possessions".
 The circumstances of Father Grandier's trial and execution have attracted the attention of writers Alexandre Dumas, père, Aldous Huxley and the playwright John Whiting, composers like Krzysztof Penderecki and Peter Maxwell Davies, as well as historian Jules Michelet and various scholars of European witchcraft.
 Most modern commentators have concluded that Grandier was the victim of a politically motivated persecution led by the powerful Cardinal Richelieu. Richard Dufallo
Richard John Dufallo (30 January 1933 in Whiting, Indiana – 16 June 2000 in Denton, Texas) was an American clarinetist, author, and conductor with a broad repertory.
 He is most known for his interpretations of contemporary music.
 During the 1970s, he directed contemporary music series at both Juilliard and the Aspen Music Festival, where he succeeded Darius Milhaud as artistic director of the Conference on Contemporary Music.
 He was influential at getting American works accepted in Europe, and gave the first European performances of works by Charles Ives, Carl Ruggles, Jacob Druckman, and Elliott Carter as well as younger composers like Robert Beaser.
 Dufallo, as conductor, also premiered numerous works by European composers, including Karlheinz Stockhausen, Sir Peter Maxwell Davies, and Krzystof Penderecki.
 He was a former assistant conductor of the New York Philharmonic, and worked closely with Leonard Bernstein from 1965 to 1975.
 He also served as associate conductor of the Buffalo Philharmonic.