Blues uses blue notes--notes that are bent, damped, otherwise altered-, to accentuate rhythmic figures, as well as the concept of repeating a melodic phrase against chordal changes in order to achieve varying degrees of dissonance--

The minor against a major is a really typical way of doing this, Playing something like a "G" on the high e string against an E major chord-- as is the raised fourth against the fifth and the seventh against the octave--