Original: Boogie woogie is a style of piano-based blues that became very popular in the late 1930s and early 1940s, but originated much earlier, and was extended from piano, to three pianos at once, guitar, big band, and country and western music, and even gospel.
Simplified: Boogie-woogie is a style of piano-based blues that became very popular in the late 1930s and early 1940s.