Yeah, skills, exactly!
Also nice to hear actual pitches in the lines, as opposed to a "general" slurviness that some/too many singers use when scatting on a tune. If done intentionally, it's cool, part of the intrinsically "vocal" thing that (I think) Larry was getting at, but too often just a way of saying, "Not necessary!!!!" and/or "Seriously? You expect me to do THAT?", but, yeah, it kinda is and yeah, I kinda do.