Sir George Christie: Opera manager who carried on the work of his father in making Glyndebourne a magical venue for music

George Christie's preordained role in life was to maintain the magic created in the 1930s by his father at their private opera house, Glyndebourne, on the Sussex Downs. He had been running the show for about a dozen years when I first went in 1969 as the guest of the widow of Ralph Vaughan Williams, Ursula, who set out our picnic under the tree where she said a nightingale would sing (it obliged). The performance was of one of the Mozart–Da Ponte operas and the programme notes had been written by James Strachey, Lytton's psychoanalyst brother. Christie kept this essential spirit of his father's opera festival he'd made in one of the family's country houses (John Christie was from a wealthy landed family in Devon, who gave him the Glyndebourne estate for his own use).

Christie's chief legacy is the new opera house he built, which opened for the 1994 season "on time and on budget." The previous 300-seat theatre was attached to the house – which, he quipped, gave him the feeling that he lived in a "semi". It had grown organically from outbuildings and garages, so the backstage arrangements were poor. He briefed nine British architects: "There is emphatically no need in rebuilding the theatre to be slavish to the style of the house; and there is, even more emphatically, no need to be slavish to the existing theatre, which has grown piecemeal over the last 50-odd years and which is architecturally a complete hybrid."

Besides bricks and mortar, Christie leaves an institution fit for use in the 21st century. Glyndebourne adheres to the highest international musical and production standards – a Glyndebourne credit on a performer's CV means a good deal to casting directors – and ticket prices reflect this. But Christie saw the importance of this private company's public role. In 1968 he overcame his own father's hostility to Arts Council subsidies and accepted a small one for the touring company, which now means Glyndebourne operates all year. In 1986, while the company performed its hit Porgy and Bess (with new, democratic surtitles) he founded Glyndebourne's wonderfully active Education Department under the dynamic Katie Tearle, which has served as a model for so many other arts enterprises.

Christie saw that black-tie-and-picnic opera, which Glyndebourne can claim to have founded, had an image problem. The class war aspect of it (his eldest son, Hector, joined the Occupy London movement and was arrested in 2012 – the tabloids called him "Britain's poshest protester") is easy enough to rebut with touring and education programmes. More difficult is the reliance on corporate generosity, and the need to reward sponsors and donors with tickets. One solution: since 1962 the policy has been to keep back 30 per cent of the seats for the general public, and, as happens at Bayreuth and elsewhere, membership of the Glyndebourne Festival Society is eventually recognised with tickets.

George Christie was born over the shop on New Year's Eve 1934. His father, John Christie, a former Eton schoolmaster, then a land-owning businessman, engaged local builders to run up an opera house for the benefit of his wife, the soprano, Audrey Mildmay. She inaugurated the stage by singing Susanna in Mozart's Marriage of Figaro while pregnant with George. The couple had spent time in Germany, especially at Bayreuth, and were impressed by what the Wagner family had achieved. He continued to visit, even during Hitler's Reich, at the same time that he was staffing Glyndebourne with Jewish refugees, including Rudolf Bing.

Following Eton, where he was a member of Pop, George went up to Trinity College Cambridge. He dropped out after taking the Italian and German papers in part I of the Tripos, however, and went to the Gulbenkian Foundation for five years, a good career move for someone who was to spend the rest of his life raising funds for the family business. He spent the 1953 and 1954 summer seasons as "producer's assistant", and at the end of 1958, owing to his father's poor health, though still only 23 became Chair of Glyndebourne Productions.

He had a splendid right-hand man, Moran Caplat, a naval officer who was the son of one of John Christie's estate managers. Caplat had experienced the saga of the abrupt departure of Rudolf Bing to found the Edinburgh Festival in 1948, and was up to speed with opera politics. George's job at first was to look after the financial and social sides, housing singers, directors and designers, and, with his wife Mary, whom he married in 1958, hosting discreet fund-raising dinners during the interval. (One of the challenges facing every Glyndebourne director is to find the place in the libretto where dinner can be inserted without doing dramatic damage.)

Superb though the Michael and Patty Hopkins' opera house is, with its glistening wood surfaces and good acoustic, Christie's contribution to the family firm cannot be measured in buildings alone. In 1970 he had the boldness to appoint Peter Hall as artistic director. Hall's 20-year tenure included some of the most memorable moments in all opera, such as Peter Sellars' Los Angeles Freeway setting of The Magic Flute, his stunning Theodora and most alarming of all, Nigel Osborne's specially commissioned The Electrification of the Soviet Union, with its libretto by Craig Raine. For the first time boos were heard at Glyndebourne, to the refreshment of the repertory and – for this was a subtle index of social mobility – the renewal of the audience.

The new house opened in May 1994 with a production of The Marriage of Figaro, the same opera with which the Festival had been founded 60 years earlier; but now the audience was 50 per cent larger. George retired at 65, handing over to his son, Augustus (Gus). Like his grandfather, Gus married his soprano, the talented Danielle De Niese. George, knighted in 1984 and appointed CH in 2001, remained a country gentleman, keen on his sheep, cattle and pug dogs – yet he was a culture hero, one of those responsible for the huge growth in the audience for opera.

George William Langham Christie, opera proprietor: born Glyndebourne 31 December 1934; Kt 1984; CH 2002; married 1958 Mary Nicholson (one daughter, three sons); died Glyndebourne 7 May 2014.