Celebrated French thriller writer Michel Bussi has released a new novel, Code Yesterday, which imagines that all the Beatles' greatest hits were actually written by a French-born woman named Yvonne McKenzie. The fictional premise serves as a commentary on the historical exclusion of women from classic rock music and songwriting, with Bussi noting that he wanted to "give women revenge" by exploring how credible it would have been for a female songwriter of humble origins in the 1960s to remain entirely uncredited whilst her work became the world's most iconic songs.

In Bussi's story, Yvonne, a customs inspector of mixed French-English heritage raised on Liverpool's Penny Lane, meets John and Paul McCartney on the day they first encountered each other in 1957. She secretly composes their hit songs over the telephone, with Bussi creating ingenious backstories for each: the feedback in "I Feel Fine" comes from a household appliance interfering with the phone line; the rhythm of "Can't Buy Me Love" originated from her whisking an egg. As compensation for her anonymity, Yvonne demands subtle French references be woven into the songs—including La Marseillaise in "All You Need is Love" and "Michelle," dedicated to her mother Micheline.