Glen Milborn Sherley (March 9, 1936 - May 11, 1978) was an American criminal who became a country singer-songwriter after his song "Greystone Chapel" was made famous by Johnny Cash in 1968.
Sherley wrote the song while in prison and it was later performed by Cash at his Folsom Prison performance, which was eventually released as the album At Folsom Prison.
Sherley was in the front row, unaware that his song was going to be played.
Sherley subsequently wrote and performed a number of other songs.
However, despite help from Cash, he was unable to adjust to life outside of prison and eventually committed suicide at the age of 42.