Original sentence: "Glass Onion" is a Beatles song about Beatles' songs."Julia" was the name of Lennon's beloved but frequently absent mother, who died during his youth."While My Guitar Gently Weeps" expresses concern over being "bought and sold," a theme in later songs about Harrison himself, such as "Handle with Care", recorded with The Traveling Wilburys.Many of the songs are personal and self-referencing; for example, "Dear Prudence" was written about actress Mia Farrow's sister, Prudence, who attended the transcendental meditation course with The Beatles in Rishikesh.Often she stayed in her room, engaged in Transcendental Meditation.Previously, no female voices were to be heard on a Beatles album, but Yoko Ono made her first vocal appearance on this record, adding backing vocals in "Birthday" (along with Pattie Harrison); she also sang backing vocals and a solo line on "The Continuing Story of Bungalow Bill" and, as noted earlier, was a strong influence on Lennon's musique concrète piece, "Revolution 9," an avant-garde sound collage that McCartney initially did not want to include on the album.Some of the songs on The Beatles mark important changes in the band's recording style