In this one it sounds like a hymn is being played in the background:    Anything would work, sweet hour of prayer, old rugged cross, amazing grace.  I'm not sure that this song has it's own melody. 
First, the correct name of the song is:
THE OUTLAW'S PRAYER... Add the word THE ...

Secondly, there is no ACOUSTIC VERSION of the song.

So change part from acoustic to WHOLE SONG

Here is the link to the song:
Here johnny is playing the song... If you notice he is capoed at the 5th fret
And not really playing much of anything ... He is also playing an electric guitar..