One to begin
On the off chance that you find yourself wondering where this phrase – most famously used by Elvis at the start of Blue Suede Shoes (1956) – comes from, wander no further.
Elvis got it from Carl Perkins’ 1955 (first) recording of Blue Suede Shoes, but it had already turned up in Bill Haley’s “Whatcha Gonna Do?” (1953) and before that in Hal Singer’s Rock Around the Clock (1950).*
Two to show
Etymologist Barry Popik has helpfully recorded the story of how Perkins came to use the saying, along with a list of occurrences in its earlier incarnation as a children’s rhyme.
Popik’s first exact match comes in an 1866 edition of The Little Corporal, which I can’t find in digital form, and it turns up quite often after that, for example in an 1888 book of rhymes for children, and in St Nicholas Magazine in 1892:
“Can you run fast? I bet I can beat you. Now, one for the money! Two for the show!” And Leslie put her foot out and began swaying her body for the start.
“I don’t want to run,” said Mildred.
“Three to make ready!” cried Leslie, warningly, and preparing to start without heeding Mildred’s protest.
But at that moment Eliza made her appearance, and called to the girls that Mrs. Morton was going.
St Nicholas Magazine, January 1892
God bless the rider
And now you know.
*Singer’s Rock around the Clock is somewhat different from the Haley’s 1954 version.