For the pianist, the simple walking bass line allowed the right hand to improvise and experiment with the melody. The boogie’s walking bass, up the scale four beats and back down the next four, up four, down four,... was repeated throughout the song. Usually played as quarter notes in 4/4 time, the bass line could be driven “eight to the bar” using eighth notes. This simple, yet driving rhythm allowed the pianist to embellish the melody line as his ear (and skill) allowed.
As boogie woogie was picked up by small ensembles, the rhythm was usually handled by the bass and rhythm guitar and the melody instruments, usually mandolin or guitar, were free to improvise as they saw fit.
If the musician has the skill and dexterity, boogie woogie is a freestyle showcase of that artistry.