Various 20th century composers felt the need to historically legitimise their innovations.
The innovations in 20th century music did not occur at random or as a result of anarchy. They are a logical link in the development of music. Both the neo-classicism of Marcel Poot and Jean Françaix and the use of dodecaphony by August Verbesselt can be understood as a deeper reflection of 18th and 19th century tradition. Both movements were a reaction to the pathetic character of Romanticism, in which the individual moment of feeling was consciously (over)accentuated. Whereas neo-classicism reverted to composition techniques from the 18th and 19th centuries, the use of atonality and dodecaphony was caused by the search for an alternative system for pitch organisation.
Tonal harmony, which experienced a huge expansion at the end of the 19th century, did not seem capable of doing this anymore.