The song chosen by the choir is "Welcome, Sweet Springtime," unofficially recognized by Barney as "good ol' 14-A."
Don Knotts intentionally sang off-key. The evidence that proves he can sing in-key is in "The Guitar Player," with guest-star James Best practicing guitar along with Sheriff Andy Taylor.
This is the first appearance of John Masters, Mayberry's Choir Director.
The choir's selection, "Welcome, Sweet Springtime,"is a real song. It was composed in 1884 by Michael Watson. Also known as "Voices in the Woods," the melody was later adapted into Anton Rubinstein's "Melody In F." It shows up twice in the film "Rhapsody in Blue" (1945), about the life of George Gershwin.
Actor Olan Soule was also the voice-over narrator of several The Andy Griffith Show (1960) sponsor spots that aired after the end-credits during season 3.