Ms. Hatto usually stole from younger artists who were not household names, although on the basis of the reviews she received, they richly deserved to be. Her recording of Chopin mazurkas seems to be by Eugen Indjic; the fiendishly difficult transcription of Chopin studies by Leopold Godowsky are actually recordings by Carlo Grante and Marc-André Hamelin; her Messiaen recordings were by Paul S. Kim; her version of the “Goldberg” Variations of Bach at least in part by Pi-Hsien Chen; the complete Ravel piano music by Roger Muraro. As reports come in, the rip-off list grows daily.

Her concerto recordings are even more brazen. The CD labels say they were made with the National Philharmonic Symphony Orchestra, always conducted by one René Köhler. Mr. Barrington-Coupe told a reporter that this was his name for a pick-up orchestra of Polish émigrés whom, he said, came out from London to record at a venue he now refuses to reveal. He declined to further discuss the orchestra on the grounds that they were employed “below union rates.” No one has yet been able to find a single reference to this René Köhler outside of the Joyce Hatto recordings, nor have any members of the orchestra come forward to confirm Mr. Barrington-Coupe’s story.

In a rapturous review of Ms. Hatto’s playing of Rachmaninoff’s Third Concerto, one critic said of the orchestra musicians: “It doesn’t matter who they are, their playing is tight and hot.” Actually, it did matter, since they have turned out to be the Philharmonia Orchestra of London, conducted by Esa-Pekka Salonen, performing with the formidable Yefim Bronfman. Her version of the Brahms Second Concerto is Vladimir Ashkenazy’s, with the Vienna Philharmonic under Bernard Haitink laboring in the name of René Köhler and his non-union Poles.

Since the news broke, some have likened the exploits of Joyce Hatto to the notorious 20th-century Vermeer forger Han van Meegeren. But the differences are significant. Van Meegeren’s success was based as much on presentation — stories of old Italian families impoverished before World War II and needing quick cash — as on artistic plausibility. After he confessed, it was not hard for anyone to see that his dreadful fakes had more in common with each other than with any original Vermeers.

Joyce Hatto, however, was not a pianistic forger. In order to forge a piano performance, she would have had to record Beethoven’s “Hammerklavier” herself and sell it to the world as a lost recording by, say, William Kapell. She was instead a plagiarist: she stole other pianists’ work and, with only a few electronic alterations, sold it as her own.

Although the critics who praised Van Meegerens’s “Vermeers” as masterpieces were in the end rightly humiliated, the same should not be true of those who praised Ms. Hatto’s recordings. They may have been fooled, but their opinions were not foolish, because the artists she ripped off played beautifully.