Answer the question at the end by quoting:

Guy Carleton, 1st Baron Dorchester, KB (3 September 1724 - 10 November 1808), known between 1776 and 1786 as Sir Guy Carleton, was an Anglo-Irish soldier and administrator. He twice served as Governor of the Province of Quebec, from 1768 to 1778, concurrently serving as Governor General of British North America in that time, and again from 1785 to 1795. The title Baron Dorchester was created on 21 August 1786. He commanded British troops in the American War of Independence, first leading the defence of Quebec during the 1775 rebel invasion and the 1776 counteroffensive that drove the rebels from the province.
On 7 April 1766, Carleton was named acting Lieutenant Governor and Administrator of Quebec with James Murray officially in charge. He arrived in Quebec on 22 September 1766. As Carleton had no experience in public affairs and came from a politically insignificant family, his appointment is unusual and was possibly a surprise to him. One connection may have been due to the Duke of Richmond, who in 1766 been made Secretary of State for the North American colonies. Fourteen years earlier, Carleton had tutored the Duke. The Duke was the colonel of the 72nd Regiment of Foot, while Carleton was its lieutenant colonel. He appointed Carleton as commander-in-chief of all troops stationed in Quebec. The government consisted of a Governor, a council, and an assembly. The governor could veto any action of the council, but London had also given Carleton instructions that all of his actions required the approval of the council. Most officials of the province at this time did not receive a salary and received their income through fees they charged for their services. Carleton tried to replace this system with one in which the officials received a regular salary, but this position was never supported in London. When Carleton renounced his own fees, Murray was furious. After Murray resigned his position, Carleton was appointed Captain General and Governor-in-Chief on 12 April 1768. Carleton took the oath of office on 1 November 1768. On 9 August 1770 he sailed for England for what he thought was a few months' consultation on issues related to the integration of Quebec into the British system. During his absence, Hector Theophilus de Cramahe, the lieutenant governor, ran the provincial government, with the aid of the first chief justice, William Hey, and the Attorney-General, Francis Maseres. The British merchants of Quebec, many of whom had become disaffected to the colonial administration under Murray, were, at least initially, of good will. The merchants would later be agent for e.g. the Quebec Act of 1774 (14 Geo. III, c.83) and finally the partition of the two Canadas in the Constitutional Act of 1791 (31 Geo. III, c.31).

When did he become governor?

7 April 1766,

Answer the question at the end by quoting:

Olivier Eugene Charles Prosper Messiaen (French: [olivje mesja]; December 10, 1908 - April 27, 1992) was a French composer, organist, and ornithologist, one of the major composers of the 20th century. His music is rhythmically complex; harmonically and melodically he employs a system he called modes of limited transposition, which he abstracted from the systems of material generated by his early compositions and improvisations. He wrote music for chamber ensembles and orchestra, vocal music, as well as for solo organ and piano, and also experimented with the use of novel electronic instruments developed in Europe during his lifetime. He travelled widely and wrote works inspired by diverse influences ranging from Japanese music, the landscape of Bryce Canyon in Utah and the life of St. Francis of Assisi.
Messiaen's next work was the large-scale La Transfiguration de Notre Seigneur Jesus-Christ. The composition occupied him from 1965 to 1969 and the musicians employed include a 100-voice ten-part choir, seven solo instruments and large orchestra. Its fourteen movements are a meditation on the story of Christ's Transfiguration. Shortly after its completion, Messiaen received a commission from Alice Tully for a work to celebrate the U.S. bicentennial. He arranged a visit to the US in spring 1972, and was inspired by Bryce Canyon in Utah, where he observed the canyon's distinctive colours and birdsong. The twelve-movement orchestral piece Des canyons aux etoiles... was the result, first performed in 1974 in New York. In 1971, he was asked to compose a piece for the Paris Opera. While reluctant to undertake such a major project, he was persuaded in 1975 to accept the commission and began work on his Saint-Francois d'Assise. The composition was intensive (he also wrote his own libretto) and occupied him from 1975 to 1979; the orchestration was carried out from 1979 until 1983. Messiaen preferred to describe the final work as a "spectacle" rather than an opera. It was first performed in 1983. Some commentators at the time thought that the opera would be his valediction (at times Messiaen himself believed so), but he continued to compose. In 1984 he published a major collection of organ pieces, Livre du Saint Sacrement; other works include birdsong pieces for solo piano, and works for piano with orchestra. In the summer of 1978, Messiaen retired from teaching at the Conservatoire. He was promoted to the highest rank of the Legion d'honneur, the Grand-Croix, in 1987. An operation prevented his participation in the celebration of his 70th birthday in 1978, but in 1988 tributes for Messiaen's 80th included a complete performance in London's Royal Festival Hall of St. Francois, which the composer attended, and Erato's publication of a seventeen-CD collection of Messiaen's music including a disc of the composer in conversation with Claude Samuel. Although in considerable pain near the end of his life (requiring repeated surgery on his back) he was able to fulfil a commission from the New York Philharmonic Orchestra, Eclairs sur l'au-dela..., which was premiered six months after his death. He died in Paris on April 27, 1992. On going through his papers, Loriod discovered that, in the last months of his life, he had been composing a concerto for four musicians he felt particularly grateful to, namely herself, the cellist Mstislav Rostropovich, the oboist Heinz Holliger and the flautist Catherine Cantin (hence the title Concert a quatre). Four of the five intended movements were substantially complete; Yvonne Loriod undertook the orchestration of the second half of the first movement and of the whole of the fourth with advice from George Benjamin. It was premiered by the dedicatees in September 1994.

what was significant about that work?
The composition occupied him from 1965 to 1969 and the musicians employed include a 100-voice ten-part choir, seven solo instruments and large orchestra.