Presley's return over and over to the song's chorus, while playing his acoustic, would be a pattern revisited during the incredible June 1968 small combo jams. When Elvis liked a piece of music, he didn't want to let it go.
Check it out!
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Elvis Presley - "Dark Moon" (unedited 1966 home demo, Los Angeles)
But ... did you know the song was a big 1957 pop and country hit for one Bonnie Guitar?

Billboard - March 30, 1957
Below is Bonnie's rendition, for those of you who've not heard it.
Enjoy!
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Bonnie Guitar "Dark Moon" (Dot 15550, March 23, 1957)
Billboard "Honor Roll of Hits" #2, June 17, 1957
Previously issued for the country market only on Fabor 4018.
Bonnie is still with us -- she lives in Tacoma, WA and just celebrated her 87th birthday on March 25.
Rock on, Bonnie!