In the early days of rock'n'roll, most records were simply the best live take a band could achieve. No overdubs, no tinkering. And some bands still like it that way. But even from the 1930s, Les Paul started experimenting with recording over his own playing so that he could play multiple parts in the same song.

From Acetate to Tape: In the 1930s, Les Paul began working on multitracking using acetate disks. Using really old-school wax disks, Les even built his own home-made disc-cutter assembly, based on automobile parts. Example? He favored the flywheel from a Cadillac for its weight and flatness. Even dentistry played a part.

"The other part we needed," recalled Les, "came from my drummer who was a dentist. One time, he was cleaning my teeth and I saw all these dental belts, so I asked where he got them and I ordered some because they were endless belts and they were perfect for isolating the flywheel, the turntable and the recording device from any vibrations in the motor or even from trucks driving by outside."

Innovation, for sure. But Les made it work, using his acetate-disk setup to record parts at different speeds and with delay, resulting in his signature sound with echoes and birdsong-like trills and riffs. In his head, Les Paul knew what he wanted to hear� and by the late 1940s he got the tools he needed.

Les Paul and Multitracking: Weird fact? Bing Crosby was one of Les's inspirations. In 1948, Les was given one of the first Ampex Model 200A reel-to-reel audio tape recording decks by crooner Crosby, and Les soon went on to use Ampex's eight track "Sel-Sync" machines for multitracking. Capitol Records released a recording that had begun as an experiment in Les's garage, entitled "Lover (When You're Near Me)," which featured Paul playing eight different parts on electric guitar. Some of them were recorded at half-speed, so they "double-fast" when played back. The b-side, "Brazil," was similarly recorded.

To Les's frustration, Sidney Bechet used multitracking (via acetate disks) in 1941 to play half a dozen instruments on his hit "Sheik of Araby." But Les took the idea further.

Les Paul and Mary Ford's version of "How High the Moon," which topped the Billboard singles chart for nine weeks in 1951, was a tipping point. It was a multi-layered, revved-up recording that highlighted not only Les's guitar virtuosity (on a Gibson Les Paul Goldtop model, naturally), but also the capabilities of multitracking. It may sound cute now, but this was a true "eureka!" moment for tape recording.