Hymn George sings: Softly and Tenderly
The "Trivia" section of this page states that "the song George sings" is the Carter Family's "Wildwood Flower." Not true! It may be that an early draft of the script mentions that classic (secular) song, but the piece that George performs is the hymn "Softly and Tenderly (Jesus Is Calling)," words and music by Will L. Thompson of Ohio, published 1880.
More trivia: It is also performed in the movie "Trip to Bountiful," and at the funeral of Dr. Martin Luther King Jr.