For many years the Beatles had not allowed any remixing of their music. They made an exception for "Yellow Submarine", though. Technicians went back to the original recordings, using new machines and ideas to make them sound better than ever before. John Lennon had died in 1980, but the surviving former Beatles all approved the new mixes. Ringo Starr was impressed most of all, and was pleased that parts of the music could be heard, that had never been heard before.