Watch the Dead Thumb online guitar lesson by Jason Loughlin from Rockabilly Survival Guide: Lead
The technique called dead thumb is more prevalent than people think in rockabilly. Yes it's more known as a solo blues concept but players like James Burton and Scotty Moore use it more than Travis picking. Classic solo "Hello Mary Lou", "Susie Q" and the rhythm for "Mystery Train" are all using dead thumb. The idea is we keep steady quarters on the root of the chord with our thumb while improvising on top. I'll show some drills for developing independence, incorporating hammer ons and pull offs and not just relying on open bass strings.