On July 25, 1965 Bob Dylan played a brief set at the Newport Folk Festival that evoked boos and changed rock music.

His sin: rocking.

Leading up to the summer of 1965, the singer songwriter had released four folk albums in his fledgling young career: Bob Dylan (1962), The Freewheelin' Bob Dylan (1963), The Times They Are a-Changin' (1964), and Another Side of Bob Dylan (1964).

But in the spring of 1965 he provided a little foreshading to what would happen that fateful summer night in Newport, Rhode Island, when he released Bringing It All Back Home, an album that on one side contained folk songs with acoustic instruments; but on the flip side, hold your hat, were electric songs.

Those electric tunes, sacrilege to purists who previously held Dylan in the highest regard as a folk protest singer, included "Maggie's Farm," the first thing he sang in the set.

Some who were there say the booing started before Dylan could sing the song about not wanting to be held back by a selfish authority figure who didn't want him to grow.

They say the booing occurred in part because they could see the amplifiers, bass and electric guitar get set up. And they were also reacting to the squeaky feedback as the instruments were being plugged in.

Then there were those who said it was the press who booed, others say it was the other folk musicians, and some say the booing was because the sound was awful and mixed poorly.

Others claim there was no booing at all, either before, during or after the 15 minute set.

"They certainly booed, I'll tell you that," Dylan said at a San Francisco press conference five months later. "You could hear it all over the place. I don't know who they were, though. And I'm sure whoever it was did it twice as loud as they normally would."

He said they didn't boo in Texas, Atlanta, Boston, or Minneapolis, his hometown.

But they've done it in lots of other places, he said, holding a cigarette.

"They must be pretty rich to be able go someplace and boo," Dylan said to the laughter of the press.

Despite the levity, Dylan didn't return to the Newport Folk Festival for 37 years. And when he did he came in a wig, a beard, and a scowl.

But he did play for two hours: a seven-song acoustic set followed by a 16-song electric set.

The 1964 sunburst Fender Stratocaster Dylan rocked at Newport '65 is on loan to the Metropolitan Museum of Art, but not on display.