This is what we found on Wikipedia regarding the Zaho de Sagazan:

A chanson (UK: , US: ; French: chanson française [ʃɑ̃sɔ̃ fʁɑ̃sɛːz] , lit. 'French song') is generally any lyric-driven French song. The term is most commonly used in English to refer either to the secular polyphonic French songs of late medieval and Renaissance music or to a specific style of French pop music which emerged in the 1950s and 1960s. The genre had origins in the monophonic songs of troubadours and trouvères, though the only polyphonic precedents were 16 works by Adam de la Halle and one by Jehan de Lescurel. Not until the ars nova composer Guillaume de Machaut did any composer write a significant number of polyphonic chansons.

A broad term, the word chanson literally means "song" in French and can thus less commonly refer to a variety of (usually secular) French genres throughout history. This includes the songs of chansonnier, chanson de geste and Grand chant; court songs of the late Renaissance and early Baroque music periods, air de cour; popular songs from the 17th to 19th century, bergerette, brunette, chanson pour boire, pastourelle, and vaudeville; art song of the romantic era, mélodie; and folk music, chanson populaire. Since the 1990s, the term may be used for Nouvelle Chanson, a French song that often contains poetic or political content.