Alternating bass is a technique in which the thumb alternates between two or more bass notes, while the fingers play a melody on the higher strings. The technique is used in several musical styles, e.g. Piedmont Blues (Mississippi John Hurt) and is sometimes called Boom-Chick rhythm. The Boom-Chick rhythm gets really groovy when you emphasize beat two and four. You can do this by playing the corresponding notes a bit louder or by hitting more than one string on beat two and four. Big Bill Broonzy, a Country Blues guitarist from the early days, was famous for his strongly accented alternating bass.