Art music (or serious music[1] or erudite music), is an umbrella term generally used to refer to musical traditions implying advanced structural and theoretical considerations[2] and a written musical tradition.[3] The notion of art music generally refers to a frequent musicological distinction that musicologist Philip Tagg refers to as an "axiomatic triangle consisting of 'folk', 'art' and 'popular' musics".[4] As Tagg explained, each of these three is distinguishable from both others according to certain criteria.[5] In this regard, it is frequently used as a contrasting term to popular music and folk music.[