Nilsson was born in Brooklyn in 1941. His father abandoned the family, which bounced around and finally landed in southern California. Nilsson clearly was a unique character. The Beatles were big fans. According to the profile at his site, he had a close friendship with each. The highest profile of these was with John Lennon.
The profile also said that Nilsson jumped between genres and didn’t create a strong public profile because he never toured. A commenter at the YouTube for “Coconut” (below) wrote that he sometimes played open mics with anyone who would show up for such nights at a bar frequented by both men.
The sense is that Nilsson had a flippant attitude. Other artists took him seriously, however. The profile at his site says that he was recorded by Joe Cocker, Neil Diamond, Diana Ross, Barbra Streisand, Glen Campbell, Brian Wilson, Ella Fitzgerald, Three Dog Night and others. Nilsson won two Grammy Awards. Nilsson died in 1994 at the age of 52.