One of my favorite Warner Bros. cartoons, and doubly interesting because it not only uses real jazz musicians, but, as Dave pointed out, all the vocals are done by Stan Freberg, not Mel Blanc, which makes it exceedingly rare in the history of Looney Tunes. A few years back, when the Looney Tunes Golden Collection, Volume 2 came out and I finally got a copy of this on DVD, I used to drive my family nuts playing "The Three Little Bops" over and over.
Also, a friend of mine demonstrated an impressive memory when, at the time, I mentioned this cartoon to him. He still didn't have the DVD set, but immediately said, "You got to get hot to play real cool!" This shows just how hip the WB animators and writers were back then.