Next to Son House and Charley Patton, no one was more important to the development of pre-Robert Johnson Delta blues than Tommy Johnson. Armed with a powerful voice that could go from a growl to an eerie falsetto range and a guitar style that had all of the early figures and licks of the Delta style clearly delineated, Johnson only recorded for two years -- from 1928 to 1930 -- but left behind a body of work that's hard to ignore.