There's a hoary old musical story about an American professor of musical composition who recommended to his students that whenever they were stuck they could always turn to one of the established masterpieces and write it out backwards. No one, he said, would ever notice.
The furore over the recent revelations about fake recordings issued under the name of the British pianist Joyce Hatto would seem to prove his point. Plagiarism, fraud and forgery are nothing new in the musical world. It's only when the scale is exceptional or when famous names are involved that the phenomenon attracts widespread attention.
The great violinist Fritz Kreisler created quite a scandal in 1935 when he owned up to having passed off original compositions of his own as being the work of various masters from the 18th century. His public admission brought an explosion of critical wrath, notably from the critic of the Sunday Times, Ernest Newman. Kreisler's deception was mostly about small pieces, many of which, incidentally, have retained their popularity to this day, and are still earning royalties for Kreisler's estate.
A Parisian musical family took on a rather grander challenge. Francis, Henri and Marius Casadesus were involved in the publication of concertos bearing the names of Mozart, Handel, Johann Christian Bach and Carl Philipp Emanuel Bach. Henri had founded the Société des Instruments Anciens with the celebrated composer Camille Saint-Saëns in 1901 and, as a viola-player, he was active in the revival of the obsolete but quaintly-named viola d'amore. He took it upon himself to compose the viola concertos that some altogether more famous names had inconveniently neglected to write.
The family's greatest success, however, was in the early 1930s, when a composition by Marius, the Adelaide violin concerto, was pawned off as the work of the 10-year-old Mozart. The nickname stemmed from the dedication - to Adelaide, eldest daughter of Louis XV. It was not until 1977, in a court case about royalties for the orchestration, that the author came clean and owned up to the hoax. He had, in fact, written the whole thing himself.
Back in the 1930s the "discovery" was taken very seriously indeed. The 18-year-old Yehudi Menuhin recorded the concerto for His Master's Voice in 1934, using cadenzas by the German composer Paul Hindemith. And as late as 1956, in The Mozart Companion published for that year's Mozart bicentenary celebrations, the musicologist Friedrich Blume was still defending the work's claims to authenticity. The musicologically more sober Alfred Einstein, author of a famous study of Mozart, had already rubbished the whole escapade as "a piece of mystification à la Kreisler".
One of the editors of The Mozart Companion was H.C. Robbins Landon, the 20th-century's greatest advocate of the music of Haydn. He became embroiled in one of the big forgery stories of the 1990s, when he put his weight behind the authenticity of six "lost" piano sonatas by Haydn, discovered by Winfried Michel, a German music teacher from Münster.
"The sonatas you sent me," responded Michel's original point of contact, the pianist and scholar Paul Badura-Skoda, "are so original and contain so many unexpected and surprising turns that I feel quite sure that Haydn is the composer." The discovery made the front page of the London Times in December 1993. And in January 1994 Robbins Landon endorsed them in the BBC Music Magazine, claiming that they "clarify in a peculiarly striking way Haydn's search for a new musical language of strength and beauty which was to emerge as the beginning of the Viennese Classical style".
In no time at all, however, they had become "a rather sinister forgery" - all the work of Michel, save for the opening bars of each sonata, which are known from a catalogue that Haydn kept of his own music. The irrepressible Badura-Skoda not only performed the forgeries in public, but also recorded them, on a disc that's amusingly emblazoned, "Unauthorised Version".
Michel at least had actually done some composing. In 2001 the Atlanta-based French composer Tristan Foison passed off a 1963 Requiem by Alfred Desenclos, note for note, as his own. And scholars have struggled to unravel the true authorship of works unscrupulously attributed to names such as Haydn (a number of early string quartets), Mozart (the Twelfth Mass, which once rivalled his Requiem in popularity), and Beethoven (the Jena symphony, discovered in 1909).
The recently-exposed Joyce Hatto fraud dwarfs all these others by virtue of its scale. Hatto, an English pianist who died last June at the age of 77, had a minor career and had stopped performing in the 1970s. But in the past few years over 100 CDs of her work - more than the recorded legacies of the likes of Arthur Rubinstein or Vladimir Horowitz - appeared on the Concert Artists label, run by her husband William Barrington-Coupe. But, as Barrington-Coupe now admits, the astonishing flow of discs was achieved only by an unprecedented degree of pilfering from other performers' work.
The great and the good have had their recordings appear under Hatto's name, and the pianist Gary Graffman, a former president of Philadelphia's Curtis Institute of Music, has quipped: "If none of these turn out to be something that I did, I'll be deeply insulted."
It was the internet that helped unravel the truth about Hatto. The American composition professor's advice, so the story goes, led to his own unmasking. His students had a good look at his most famous composition - from back to front, of course. They recognised it straight away as Sibelius's Fifth Symphony.