Peter Bogdanovich said he came up with the movie title while listening to the song. There's more to it than that. The song is the screenplay in miniature. The honky-tonk life, it's there; the Barnum and Bailey circus, it's there in the movie; the canvas sky; the penny arcade melody. The phoniness would be made real if Moze believed in Addie; without love it's all sham. Without love, "It's phony, it's plain to see". But, "How happy I would be, If you believed in me." Ima cry.
Say it's only a paper moon
Sailing over a cardboard sea
But it wouldn't be make-believe
If you believed in me
Yes, it's only a canvas sky
Hanging over a muslin tree
But it wouldn't be make-believe
If you believed in me
Without your love
It's a honky tonk parade
Without your love
It's a melody played in a penny arcade
It's a Barnum and Bailey world
Just as phony as it can be
But it wouldn't be make-believe
If you believed in me
Say, it's only a paper moon
Sailing over a cardboard sea
But it wouldn't be make-believe
If you believed in me
Yes, it's only a canvas sky
Hanging over a muslin tree
But it wouldn't be make-believe
If you believed in me
Without your love
It's a honky tonk parade
Without your love
It's a melody played in a penny arcade
It's a Barnum and Bailey world
Just as phony as it can be
But it wouldn't be make-believe
If you believed in me
It's phony, it's plain to see
How happy I would be
If you believed in me