What do we call the overall structure or design of a song?

This is Music, I don't know what category Music is

Musicology or Ethnomusicology is the study of music in its cultural context. It is often considered as the anthropology or ethnography of music. There are sub-disciplines in music. Musicology also has two central, practically oriented sub-disciplines with no parent discipline: performance practice and research (sometimes viewed as a form of artistic research), and the theory, analysis, and composition of music. Musical knowledge is applied in medicine, education, and music therapy-which, effectively, are parent disciplines of applied musicology.