Classification of "Natural Singing Method" and Chinese Vocal Music Singing Method

The concept of Style Singing Method is derived from CCTV young singers' contest in musical field in recent years.There are four kinds of vocal singing methods plus musically recognized folk singing,beautiful voice and popular singing.The classification of singing methods has its intrinsic rules.So what is the concept of Natural Style Singing? Hardly can anyone make an accurate exposition on its intension and extension.Therefore,it is a vague concept and not worth advocating.That raises the reconsideration of the classification of the singing methods,which is an issue we have to explore.