Wow, good on Rick for this one! I have played harp 45 years and was fortunate to be full-time pro at age 20. I have also spent my several years 3 hours per night working on all the Little Walter Classics. For bands I have been in Bluegrass, Country, etc. and had my own Swing/Jazz/Blues band 10 years. So many "takes" on Little Walter songs, you hear the parts copied note-for-note (and some of those like Barath are smokin) but in later choruses folks throw in some of their own licks, good but it looses some swing. This playing Rick, with his borrowing from other takes, songs, playing "out of sequence" really holds the vibe. Would be easy to imagine this being another of Little Walter's alternate takes. great swinging interpretation.
Dennis Gruenling had Joe Filisko on his webinar Saturday-Joe was stating how Sonny Boy One's timing was impeccable,both phrasing on harp and vocally.
For Rick,Kim,Dennis,Rod and Joe,I think the same holds true. Your not going to pull any of this sort of playing off without great timing. A great backing band helps,but when you can lead a band like any of those mentioned,timing is your best friend. And they have it in spades!