Three Dots and a Dash was a cocktail invented by Donn Beach at the end of World War II to celebrate V ictory by the Allied powers.
Recipes for it can be found online with original variations using three cherries (the dots) on a skewer, and a short slice of pineapple (the dash) mixed in. Some of the other ingredients are quite uncommon; at least today.
Sort of a high-octane punch.
And speaking of punch, the Punch Brothers - a "bluegrass" group from Brooklyn NY (I know, I know) - recorded a song called Three Dots and a Dash.
A careful listening of the song discerns no Morse-like rhythms to my ear.
But the music ain't bad, though it's more like Canadian Maritimes-meets-Scots-Celtic rather than anything I'd call bluegrass, though the instruments are the same as those you might find on a West Virginia porch on a Saturday evening.