The forthcoming Rubber Soul Special Edition, which comes out October 2, will include a previously unheard John Lennon song. A home demo of “Little Girl” was discovered on a tape reel from Lennon’s archive, and so little was known about it that there hadn’t even been whispers of its existence. Lennon onstage during the Beatles’ rehearsal for their third appearance on The Ed Sullivan Show, August 14, 1965. Speculation about the inspiration for the mysterious little girl ranges from a postcard sent by a Japanese fan to a nod to Brian Wilson’s “The Little Girl I Once Knew.” “Little Girl” isn’t the first Lennon demo to surface decades after it was recorded, and, judging by this latest discovery, it may not be the last.