Before the beginning of the new millenium, over the past three decades, jazz has been undergone major changes in the development. From the 70s we can see the fragmentation of jazz and the birth of many polystyle music formations. Jazz has become more open to other genres and has begun to create so called jazz fusion. Currently, artists go even further with a fusion and create eclectic projects that combine not only genres and styles, but also different types of art. Richard Lawn, theorist, talks about the complexity of gripping developments in recent decades, as we do not have enough distance to define some of the trends that are still subject to change. Clearly, jazz is not dead. But its development does notmove in the direction of one stylistic trend as it has been in the past. The development of jazz has changed in the last two decades. One of the most prominent changes is the abandonment of the swinging rhythm section that laid foundation of modern jazz in the first half of the 20th century and continued as a basic rhythmical jazz model across the development of the post-bop period. The swing rhythm did not dissapear completely from the phrasing, but the so-called hard swinging rhythm section holds its stance mainly in the mainstream. The change of the developmental paradigm and its associated phenomenon – globalization – has contributed to the great transformation. Jazz ceased to be a matter of the American continent and its development moved to Europe and other countries in the world. Thankfully to this situation, different national traditions have been implemented in jazz, which resulted in the enrichment of the musical language and the instruments. The transformation has also been made in aethetics and sound that influence different genres and current technological trend. Some theoreticians, artists and jazz journalists consider these tendencies as separation from the direct development of jazz. These new trends have emerged in the 1980s but they have gradually become more intense and became the main elements predicting developments in the new millenium. Theoretician Mervyn Cooke has expressed this period as a period when jazz enters the world of diversity but also the unclear and unpredictable future.