Les Paul died today - he was 94. He was known as one of the inventors of the electric guitar, which became the essential instrument of rock 'n' roll. Just as important, he also developed overdubbing and multi-track recording.

You can hear it on his hit records with his wife, Mary Ford (who died in 1977). She harmonizes with herself in the 1951 Capitol recording "How High the Moon," #1 for nine weeks. I love identifying unique times in media history, when something was accomplished, some miracle of communication, that had never been done before. The first time a message was sent at the speed of light (via the telegraph) ... the first time someone looked at a face captured in a photograph, not as an artist might have rendered it but as it literally was ... those kinds of things. Harmonizing with your own voice may have been a more minor, but no less profound and usually more beautiful kind of extraordinary invention. It just couldn't have happened without the technology. It was never heard in a purely natural world.

And that, too, changed the course of rock 'n' roll. The Beachboys, the Beatles, all the great harmony groups overdubbed to their own voices, and used more sophisticated multi-track recording techniques (8 tracks, in the case of the Beatles on Sgt. Pepper) to keep all the voices uniformly present and clear.

I've been teaching about Les Paul and his impact in my "Into to Communication and Media Studies" and "Intro to Mass Media" courses for more than 30 years. I've always remarked how good it was that he was still alive. This Fall I'll have to say, the late Les Paul. But his music will never be late. Because through the other miracle of recording - that of any recording of sound - we'll always be able to hear it, whenever we like...