Until Jimmy Blanton joined Duke Ellington in 1939, the bass player played either two or four notes to a bar and played very simple lines, mainly the roots and fifths of the chords.  There was hardly ever a bass solo, as these demanded more technique from the players as well as some entirely new techniques from recording engineers.

Blanton satisfied his listeners with the bass parts that he played, but while accomplishing this he also played tasteful, interesting lines.  He used eighth notes and sixteenth notes without ever sounding clumsy on the instrument, and he also proved that he could bow well.  Although he died early, Blanton laid the foundations for all bass players who followed.