The concept of the intensity of artistic life provides answers to the question of how a great artist affects the evolution of artistic life. Upon the earlier analysis (based on the creativity of 4511 European composers of the XVI-XX centuries) we concluded that there are six versions of evolution of the intensity parameters: rise, decline, dissipation, accumulation, external growth, external destruction. The version of evolution often seems to be «made» almost exclusively by this small group of composers. We regard this phenomenon as an «evolutionary genius». To measure the «evolutionary genius» we would suggest a method based on the concepts of fuzzy sets. The most favorable version for evolutionary genius is rise. Accumulation is a less favorable version for evolutionary genius. The other versions of evolution are unfavorable for evolutionary genius.