Watch the Breakdown 15 - 20 online guitar lesson by Tim Sparks from Roots, Rags & Blues
Jelly Roll Blues was one of the first jazz compositions to be published, in 1915. Morton said the "Original" Jelly Roll Blues was written in 1905. It is a rich set of variations on a 12 -bar Blues. Compared to the streamlined structure of the Mississippi Blues, it also represents a link between the music of the traveling Minstrel and Vaudeville Shows of the late 19th century and the popular jazz and blues of the early and mid 20th century.
This very old blues chord harmony reminds me of some of Charlie Parker's Be-Bop Blues chord substitutions.Two good web links to learn more about early or "Classic" Jazz are jass.com
Some good books on this subject are "Early Jazz" by Gunther Schuller, "Blues People" by Leroi Jones (Amiri Baraka), and "Really the Blues" by Mezz Mezzrow.