The lyric works through a series of poetic loneliness images — the whippoorwill too blue to fly, the midnight train whining low, the moon hiding its face — that pull country songwriting into the territory of older Anglo-American ballad poetry. Williams reportedly told his stepson the song was written about his troubled marriage to Audrey Williams during the period leading up to their separation.

The song crossed into the bluegrass repertoire almost immediately. B.J. Thomas’s 1966 cover charted at No. 8 on the country chart and No. 22 on the Hot 100. Bluegrass acts from the Stanley Brothers through the Lonesome River Band have covered it, and it remains one of the most-called slow vocal pieces in the modern roots-music canon.