Yo Ko, John Lennon's widow contributed to the breaking up of the legendary rock band the Beetles. Yo Ko was a wanna-be artist and singer who was not a smart person, in fact, she was quite stupid and ignorant in her tastes. Yo Ko help end an era that contributed to great music. John Lennon, god bless his soul, had a nutty side to him for marrying such a dark and crazy person.