refurbish the cathedral pipe organ and renovations to the Choir House have already been completed, providing better facilities for choristers. Improvements are planned to the fabric of the library buildings and to the cathedral's audio-visual and lighting systems which will significantly benefit visitors including the disabled, visually impaired and hard of hearing. The appeal also aims to develop the outmoded workshop area and stained glass studio, in order to ensure the survival of Canterbury as a centre of excellence for vital craft skills and to promote a sustainable maintenance base for work on the cathedral which can be viewed by the public. The fundraising group is the Canterbury Cathedral Trust, an independent, registered charity (1112590) seeking funds to provide conservation, craftsmanship, music and education. Since mid-2017, the Chief Executive has been Sarah Frankland. The Trust was able to obtain the £24.7m needed for The Canterbury Journey multi-year restoration programme which should be completed in 2021. In 2016–17 the Trust received £3.66m in donations and an additional £1.61m had been pledged for future projects. The next plan was to raise funds to restore and improve the Quire organ by 2020. In 2017, the cathedral was planning to have the new Welcome Centre open in 2019, with exhibition spaces and viewing gallery. Police service The cathedral has its own police service, known as the Canterbury Cathedral Close Constables. They are attested Constables, with powers of arrest, who police and protect the Cathedral and Close. They also work with Kent Police. Music Polyphonic music written for the monks of Christ Church Priory, now Canterbury Cathedral, survives from the 13th century. The cathedral may have had an organ as early as the 12th century, though the names of organists are only recorded from the early 15th century. One of the earliest named composers associated with Canterbury Cathedral was Leonel Power, who was appointed master of the new Lady Chapel choir formed in 1438. The Reformation brought a period of decline in the cathedral's music which was revived under Dean Thomas Neville in the early 17th century. Neville introduced instrumentalists into the cathedral's music who played cornett and sackbut, probably members of the city's band of waits. The cathedral acquired sets of recorders, lutes and viols for the use of the choir boys and lay-clerks. Organ The organ at Canterbury is of four manuals and is in both south and the north quire aisles, as