Premise: John Winston Ono Lennon , ( born John Winston Lennon ; 9 October 19408 December 1980 ) was an English guitarist , singer , and songwriter who co-founded the Beatles , the most commercially successful and musically influential band in the history of popular music . After his marriage to Yoko Ono in 1969 , he added `` Ono '' as one of his middle names .
Hypothesis: John Lennon was married before 1987.
Label: ENTAILMENT