Baby Beats: This band is hip deep in cool music for children, San Jose Mercury News, 6 Sep 2007, Yoshi Kato.
A spate of commenters have been using the word cool, a word I use frequently myself. I had always thought cool originated with the jazz and beatnik movements that thrived at the end of WWII. I have vague memories of the phrase “Cool, Daddy-O!” cropping up in old Elvis movies or on that hip detective show 77 Sunset Strip. They all helped take the word mainstream, but its origins go back much farther, according to the Oxford English Dictionary.
cool, adj: excellent, a slang superlative meant to indicate approval or to suggest exceptional qualities. Originally used by African-Americans, e.g. 1884, J A Harrison’s book Negro English, “Interjections… Dat’s cool!” Noted in the July 3, 1948 edition of the New Yorker, “The bebop people have a language of their own… Their expressions of approval include ‘cool’!”
Cool seems to be that rare slang term that has entered the mainstream. Way cool!