The Beatles should be well-known by now. They are a British rock band that lasted from the 1950s (when they were called The Quarrymen) to their split in 1970 (documented in the film Let it Be). Their albums have sold millions across the world, and their 1967 record Sgt. Pepper's Lonely Hearts Club Band is widely considered to be the greatest album ever recorded.
In 1969, as they were recording their final proper album, Abbey Road, during the recording of the track "Here Comes the Sun", guitarist George Harrison did a guitar solo that was cut from the released track. This solo went unheard for years until it was discovered during a recording demonstration in 2012 by George Martin, Giles Martin, and Dnhani Harrison. This can be found on the Blu-Ray/DVD Deluxe Edition of Martin Scorsese's George Harrison: Living In The Material World.