The US version included the "Penny Lane" promo version with the extra trumpet ending and a version of "I Am the Walrus" with extra beats that weren't on the standard US albums.
When Capitol Records in America saw the UK success, they realized the British tracklist wasn't "rare" for Americans. They decided to build their own version, which became a treasure trove of alternate mixes and studio oddities. The Beetles Rarities rar
The story of the is actually two different tales across the Atlantic, born from a time when "unreleased" tracks were the holy grail for fans before the internet made everything accessible. The UK Origins (1978) The US version included the "Penny Lane" promo