Robert Crumb (known as R. Crumb), born in 1943, became one of the premiere cartoonists (graphic novelists) of his generation. He became famous for such characters as Mr. Natural, Fritz the Cat, and “Keep on Truckin”, but was also a musician and passionate about rootsy forms of blues, jazz and country. And after a couple decades making comic books, he began penning a series of tribute portraits of early heroes in these genres.

Crumb’s Heroes of Blues, Jazz & Country began in the 80s with a series of illustrated trading cards, as you can see in the video below (which only covers the blues and jazz corners of the triangle). The first cards, “Heroes of the Blues,” came attached to old-time reissues from the Yazoo record company. Eventually expanding the cards to include jazz and country, working in each category from old photos or newsreel footage, Crumb covered quite a lot of musico-historical ground. Archivists and authors Stephen Calt, David Jasen, and Richard Nevins wrote the short blurbs. Finally Yazoo, rather than issuing the cards individually with each record, combined them into boxed sets.
– OpenCulture.com

Here is the full article on OpenCulture:
https://www.openculture.com/2013/10/r-crumbs-heroes-of-blues-jazz-country-features-114-illustrations-of-the-artists-favorite-musicians.html

Finally, here is a link to a charming video made from the Blues Heroes collection (the original artwork for which was somehow lost, and which Crumb had to painstakingly recreate years later).
https://youtu.be/c-D0K1u-4Aw