From Simple English Wikipedia:

John Lennon was an English musician, singer and songwriter. He was a member of the English rock band the Beatles. After the Beatles stopped making records in 1970, he lived in the United States with his wife Yoko Ono, and continued his music career up until his death in 1980.

On December 8th 1980, Lennon was shot dead as he was going into his home, by a man named Mark David Chapman who was mentally ill.

Fans all over the world mourned Lennon’s death. It made them feel that a special part of their lives was gone. Many met in New York’s Central Park, near where Lennon and Ono lived, to say their goodbyes. There is now a garden in Central Park in Lennon’s memory called “Strawberry Fields” after one of Lennon’s most popular songs.

Here’s “Strawberry Fields” by the Beatles:

And here’s John Lennon’s most famous solo song, “Imagine”: