<p>Musical improvisation, especially in jazz, is a unique form of creativity that requires active interaction between different brain networks. In contrast to the performance of pre-learned musical parts, improvisation is characterized by reduced functional connectivity between the executive control networks (ECN) and the default mode network (DMN), allowing bottom-up processes to guide creative behavior. This phenomenon, known as hypofrontality, contributes to reduced cognitive control and facilitates spontaneous generation of ideas. The aim of the present review was to analyze possible neural mechanisms underlying musical improvisation, drawing on studies conducted in a number of musical genres, primarily jazz. Study results have shown that improvisation is associated with reduced cognitive control, allowing musicians to generate new musical ideas with minimal interference from executive functions. At the same time, performance of prelearned music requires a higher level of cognitive evaluation and control, which is associated with higher functional connectivity of the ECN and DMN. Of particular interest was the finding that imaginary improvisation activates the same neural networks as real performance, highlighting the importance of self-referential processes in creativity. These findings support the hypothesis that improvisation activates unique neural mechanisms involved in facilitation of spontaneous creativity and the free flow of ideas.</p>