The type of drums used in a song is unique to each genre, and it is sometimes only the beat and rhythm that dictate how a song will be classified. Some songs don’t even require a steady tempo or the use of beats to become a “song”, but popular music and the types of music we listen to on the radio typically have some type of rhythm that we have come to expect. The roots of rhythm and beats can be traced back to perhaps the earliest man, who somehow understood that every human being was able to respond to a rhythm. Percussive drums are naturally the more organic way or producing beats, and even modern beat machines are designed to simulate that effect.
What is great about digital beat making units is how easy they can be to use. Creating a melody on a piano is quite difficult in comparison, and requires and good ear as well as some sort of musical sense. A unit like the Nord Drum is small and compact, and it will keep rhythm in ways that humans can only dream of. The second version of this unit allows a virtual drum set to be added, bringing back the natural percussive element that it spawned from.
http://createdigitalmusic.com/2013/04/nord-drum-2-playable-drum-synth-gets-more-sound-options-nord-pad-companion-photos/