British music writer Jon Wilde picked up on an old rumor for his Guardian blog — that the 29 recordings blues pioneer Robert Johnson made in 1936 in San Antonio and in 1937 in Dallas at 508 Park Avenue have actually been played too fast. His post took off, partly because netsters had been putting up slowed-down versions and debating them for several years now.

Johnson tells WNYC’s Soundcheck that he actually put off investigating or writing about the theory because, as he says, he was horrified that he may have been misled by something so close to his heart. “It’s rather like hearing Citizen Kane was originally shot in color and we’ve been watching it wrong all these years.”

After a few listens, he says, “I wouldn’t say I’m absolutely convinced. But this isn’t about absolutes … Maybe there is a point.”

In his blog post, Wilde writes, “the common consensus among musicologists is that we’ve been listening to Johnson at least 20% too fast” — that “the recordings were accidentally speeded up when first committed to 78 [rpm], or else were deliberately speeded up to make them sound more exciting.” But as the Wikipedia entry on the controversy notes, Wilde “does not give a source for this statement.”

Wikipedia goes on,  however, quoting former Sony music executive Lawrence Cohn, who won a Grammy for the label’s 1991 reissue of Johnson’s works. He acknowledges “there’s a possibility Johnson’s 1936-37 recordings were speeded up, since the OKeh/Vocalion family of labels, which originally issued the material, was ‘notorious’ for altering the speed of its releases. ‘Sometimes it was 78 rpms, sometimes it was 81 rpms,’ he says. It’s impossible to check the original sources, since the metal stampers used to duplicate the original 78 discs disappeared years ago.”

In fact, other recording artists’ works have been released or re-mastered at the wrong tempo — including, Wilde says, the Rolling Stones and the Doors, and the artists only realized this later.

But Elijah Wald, author of Escaping the Delta: Robert Johnson and the Invention of the Blues, comments on the Soundcheck report, saying that when he wrote his book, he was familiar with this theory, and there’s no truth to it.

“First of all, anyone who understands the technology of the period knows that it is simply impossible that all of his recordings, made at two separate sessions, released and unreleased, would have been sped up a consistent amount, unless that was standard policy for the record company, which it was not.

Second, for seventy years there have been people alive who heard Johnson live, and none of them ever mentioned his recordings sounding too high or fast. This story begins and ends with the fact that some modern listeners think that Johnson sounds better if you slow him down. That’s fine, but it’s entirely about their taste, not about Robert Johnson.”

The Soundcheck interview with Wilde thoughtfully includes two different speed-versions of “Crossroads,” which Johnson recorded in San Antonio in 1936. The slower version does make Johnson sound throatier, even, well, bluesier. But then Soundcheck host John Schaefer demonstrates what even an 18 percent difference in speed can mean to his own voice and argues, it’d have been hard to overlook the Chipmunk-like change.