As a mandolin enthusiast, I was particularly intrigued when I heard what appeared to be a mandolin in the song "The Continuing Story of Bungalow Bill". Upon researching the matter however, I discovered the following:
Though no Beatles recording uses a real mandolin, "The Continuing Story of Bungalow Bill" uses a simulated one. Each verse ("We went out tiger hunting...", "Deep in the jungle...", "The children asked...") is accompanied by a simulated tremoloed mandolin played on the mellotron, an early sample-playback keyboard, a predecessor to the modern synthesizers. This was added by Chris Thomas, George Martin's assistant. George Harrison would use the mandolin in his post-Beatles career, but as far as I can tell never used the instrument prior to 1970.
This blog is a workshop for developing my analyses of The Beatles' music.