The notion of a special " feel " ( rather than a set of rules ) that defines the musical style is common in non-Western music, especially the African tradition . " Flow is as elemental to hip hop as the concept of swing is to jazz . " Just as the jazz concept of " swing " involves performers deliberately playing behind or ahead of the beat, the hip-hop concept of flow is about " funking with one's expectations of time " that is, the rhythm and pulse of the music . " Flow is not about " what " is being said so much as " how " one is saying it ."
