Given the following context:

While Lennon and Starr remained consistently friendly during the years that followed the Beatles' break-up in 1970, his relationships with McCartney and Harrison varied. He was initially close to Harrison, but the two drifted apart after Lennon moved to the US in 1971. When Harrison was in New York for his December 1974 Dark Horse tour, Lennon agreed to join him on stage, but failed to appear after an argument over Lennon's refusal to sign an agreement that would finally dissolve the Beatles' legal partnership. Harrison later said that when he visited Lennon during his five years away from music, he sensed that Lennon was trying to communicate, but his bond with Ono prevented him. Harrison offended Lennon in 1980 when he published an autobiography that made little mention of him. Lennon told Playboy, "I was hurt by it. By glaring omission ... my influence on his life is absolutely zilch ... he remembers every two-bit sax player or guitarist he met in subsequent years. I'm not in the book."Lennon's most intense feelings were reserved for McCartney. In addition to attacking him with the lyrics of "How Do You Sleep?", Lennon argued with him through the press for three years after the group split. The two later began to reestablish something of the close friendship they had once known, and in 1974, they even played music together again before eventually growing apart once more. During McCartney's final visit in April 1976, Lennon said that they watched the episode of Saturday Night Live in which Lorne Michaels made a $3,000 offer to get the Beatles to reunite on the show. The pair considered going to the studio to make a joke appearance, attempting to claim their share of the money, but were too tired. Lennon summarised his feelings towards McCartney in an interview three days before his death: "Throughout my career, I've selected to work with ... only two people: Paul McCartney and Yoko Ono ... That ain't bad picking."Along with his estrangement from McCartney, Lennon always felt a musical competitiveness with...

answer the following question:

What is the last name of the person that the man that was omitted from a friend's autobiography have a musical rivalry with? 

McCartney