Frederic Seaman describes John Lennon's creative revival in a chapter in his book The Last Days of John Lennon. Seaman arrived in Bermuda some time after John visit had begun -- and he found Lennon a changed person. Lennon was excited by music -- especially reggae -- again and looking for phrases to incorporate into songs or album titles. His finds included "Living On Borrowed Time" from a Bob Marley song, and "Double Fantasy," the name of a flower.

Fred noted:

"John was clearly gaining creative momentum. He had written several new songs and rewritten some old ones. His Compurhythm drum machine had arrived, and he now decided to set up a makeshift recording studio. He wanted to buy a second tape recorder and a microphone so that he could start recording two-track demo tapes. Being unfamiliar with basic recording technique, I asked John what he meant. He explained that by using a second recorder he would be able to "double-track" his demos -- play back a tape while simultaneously adding a "live" track, and then record everything on the second tape machine."

John may have been happy with two tracks, but I wonder if he realized that he didn't have to stop there? One can keep going indefinitely -- although the quality of the sound does decrease on cassettes with each additional recording.