The assigned parts played by individual members of the rhythm section underwent radical changes.  Instead of the regular 4/4 steady rhythm heard in swing music, the drummer now used the bass and snare drums mainly for accents and punctuations.  He usually maintained an overall sound by playing eighth-note rhythms on the top cymbal.  If the accents were not spontaneous, they were played on either the fourth beat of the bar or the fourth beat of every other bar.  The more spontaneous punctuations on the bass drum were called bombs, which had to be played with great discernment to aid the impetus instead of being a distraction.

The beauty of the bop rhythm section was that the individual members were freed from duplicating one another's role.