In which period(s) did poetic expression in music become more prevalent than formerly? "?

romantic
classical
both a and b
neither a nor b

A  documentary film  is a nonfictional motion picture intended to document some aspect of reality, primarily for the purposes of instruction, education, or maintaining a historical record.example: farenheit 911

Musical notation is a system which is used to  visually represent music  pertaining to the ear  contend  with instruments or sung by the human voice through  the employment  of written, printed, or different symbols.in the western music tradition, the sound is represented in written form through musical notation.in musical notation, the pitch is indicated exclusively by the position of notes on the lines and spaces of the staff.