Many people, including musicians, think of the drummer's primary job as just providing a solid beat and rhythm. But I think that a drummer's job is no more involved with rhythm or beat than anyone else in the ensemble. Since the modern drum set is capable of producing unlimited tonal, melodic, rhythmic, and harmonic shading, there is no reason why a drummer cannot be every bit the equal of any other musician in adding a unique voice to music (although there are some types of music that call for "keeping the beat.")
Jazz
Before jazz, military rudiments and beats were essentially the only technique drummers had. However, it was necessary to adapt to the particular music being played, so new techniques and greater musicianship evolved. The roll was the major technique used on both the ride and snare implementing triplet feels in the music. Aside from this pattern, a drummer would have an extremely small role in the band as a whole. But drummers also soloed along with all the other instruments in the band.
Rock 'N' Roll
Now with drum sets completely developed, new styles implementing toms, cymbals, snare, bass etc. have become more advanced. Drummers like Ringo Star, Carl Palmer, Phill Collins, and Neil Peart have helped revolutionize the way these drum sets have been played.
