H. C. Robbins Landon: Musicologist celebrated for his work on Haydn and Mozart

Some lucky composers attract scholars of such assiduity of purpose that their names become linked from then on: one thinks of Henry-Louis de La Grange's work on Mahler or David Cairns' on Berlioz. That Joseph Haydn is now universally accepted as one of the great composers is down largely to the spadework of H. C. Robbins Landon – the music had long since slipped from view when he first began the pioneering research which would restore the reputation Haydn had enjoyed in his own lifetime.

Landon's first encounter with Haydn's music had occurred much earlier, when his music teacher put on a recording of the Symphony No 93 (the first of the 12 "London" Symphonies that made the composer a hero in the British capital in the early 1790s). The 13-year-old was astonished to learn that there were 103 more symphonies from the same source and determined to find out more.

He was born in Boston, Massachusetts in 1926 to a father of Huguenot descendant, William Grinnell Landon, and his wife Elsie (whose maiden name, Robbins, her son was to co-opt as part of his surname); when he was two, his parents moved to an estate in Lancaster in rural Massachusetts, where he grew up in splendid isolation. His study of music at Swathmore College in Pennsylvania ended when its Quaker administrators took a dim view of his affair with a girl student and he was expelled. Undaunted, he continued to Boston University, where Karl Geiringer, one of the world's few authorities on Haydn, was on the staff. He set aside his initial intention of taking a master's at Harvard in favour of a spell in Europe, spending the summer as the foreign-music correspondent of the Intercollegiate Broadcasting System. The die was cast.

Robbins Landon was never short of chutzpah, as his next strategic move demonstrated. He could see the importance of staying on in Europe but had conscription into the US military hanging over him. So he went to see the US Army of Occupation in Vienna and had himself taken on as a military historian; documenting the history of General Mark W. Clark's Fifth Army, founded in 1943 and the chief American force in the liberation of Italy, gave him a hands-on training in the use of primary documentation.

Returning to Boston, he was an "instigator", as he put it, in the founding of the Haydn Society in 1949, which soon released a sell-out recording of the 1802 Harmoniemesse. When money from a well-off uncle allowed him to return to Vienna, the Haydn Society moved with him, and he embarked on an ambitious double-pronged project: recording as much of the Haydn œuvre as he could – and unearthing it and publishing the enormous number of works that were languishing in archives across central Europe.

At that time only a tenth of Haydn's massive output was available in print, and the sheer scale of the task and publishing and recording all his music turned out to be impracticable. Robbins Landon nevertheless set his shoulder to it as best he could. Jonathan Sternberg, who first met him in Vienna in 1948 and "saw him almost daily for several years thereafter", was not only the conductor of many of those early Haydn Society recordings – he also found himself conscripted as chauffeur.

"I had a small car and drove him often to libraries, monasteries, churches and any sources he may have known about where Haydn manuscripts or letters might have been" Sternberg said. "There was no other subject which interested him."

Over the next few years, Robbins Landon ranged widely across what had once been the Austro-Hungarian Empire, using tenuous journalistic accreditations to bypass the restrictions of the Iron Curtain. He also prepared further critical editions of Haydn's music, chiefly the operas and masses, then as good as unknown, and worked on his first major publication, The Symphonies of Joseph Haydn, which appeared in 1955, before its author was 30.

The finest fruit of his researches was the five-volume Haydn: Chronicle and Works, which was published by Thames and Hudson between 1976 and 1980 and presents the documentary evidence of his fieldwork in loving detail. That it should appear from a publisher best known for books on art was itself a matter for comment.

Mozart had been another of Robbins Landon's early enthusiasms – the Haydn Society made the first recordings of the Mass in C minor and the opera Idomeneo, the original parts of which he had discovered – and so, when Peter Schaeffer's 1979 play Amadeus, and the subsequent Milos Forman film, generated a Mozart mythology of its own, Robbins Landon picked up his lance. The first of five books on Mozart, 1791: Mozart's Last Year, was published in 1988 and, like the later four, sold in huge quantities. Robert Henderson, reviewing 1791 in The Daily Telegraph, wrote that with Robbins Landon's "unrivalled knowledge of the contemporary source material, he has ruthlessly cut through the tangled skein of legend and mystification". The enthusiasm was indeed difficult to resist: he made musicology exciting.

But Robbins Landon could himself be cavalier with the facts. In his early days in Vienna he was fond of calling press conferences, in one of which he presented his discovery that the Haydn Cello Concerto in C was in fact by Anton Kraft; six months later called another conference to announce that he had discovered Haydn's manuscript after all. Haydn's Nelson Mass he rechristened the Lord Nelson Mass to make sure his American audiences got the point.

And if he could be ruthless with legend and mystery, he could be with people, too. His first wife – who, like his third wife, the historian Else Radant, and his long-term companion, Marie-Noëlle Raynal-Bechetoille, survives him – was airbrushed out of his Who's Who entry. And he turned his back on his former colleague Jonathan Sternberg for repeating the conductor Georg Szell's criticisms of his Haydn editions.

One commentator acidly observed that "He seems to change his wives the way a coachman changes horses" – but with his second wife, the harpsichordist and musicologist Christa Fuhrmann, Robbins Landon did enjoy a fruitful working relationship, extending beyond their divorce until her death in an air crash. None of the marriages produced any children.

His standing in the latter decades of the 20th century was such that another instance of careless scholarship did little to damage his reputation. In late 1993 he was asked to authenticate six "rediscovered" piano sonatas purportedly by Haydn. With his customary flair for publicity, he made much of their importance for Haydn scholarship – but he hadn't bothered to check the manuscripts themselves, which were soon exposed as fakes. He shrugged off the error with the merest hint of contrition, and makes no mention of the incident in his 1999 autobiography Horns in High C.

An invitation from the BBC led first to a number of programmes on the Third Programme from the 1950s onwards, and then to a series of TV presentations on collaboration first with Humphrey Burton and then Mervyn Williams, making his rounded American tones a familiar feature in British broadcasting. A later series, Maestro, on Channel 4, with John Julius Norwich, generated the book Five Centuries of Music in Venice in 1991.

After his first period in Vienna, Robbins Landon moved to an elegant villa in Buggiano Castello in Tuscany, where Handel's harpsichord sat in his front hall, and then, after another stint in the Austrian capital, he managed to buy, very reasonably, the 18th-century Château de Foncoussières in south-western France. I was visiting Hans Keller and his wife when he rang to announce the purchase, almost giggling at his good luck.

His academic positions included professorships in North America (Queens College, New York, in 1969 and the University of California, at Davis, in 1970) and, in Cardiff, the John Bird Professorship of Music at the University of Wales (1978–93); he was also a fellow of Lady Margaret Hall, Oxford (1979).

Robbins Landon's personality was as large as his substantial physical presence and could manifest itself in enthusiastic generosity of spirit. I called him once to see if he could help elucidate a technical detail to do with the knee-operated levers on the Viennese pianos of Beethoven's era. After breathlessly relating everything he thought might help me, he brushed aside my thanks: "Not at all – that's what we're here for!"

Martin Anderson

Howard Chandler Robbins Landon, musicologist; born Boston, Massachusetts 6 March 1926; married firstly (divorced), 1949 Christa Fuhrmann (deceased), 1977 Else Radant (divorced); died Tarn, France 20 November 2009.