Le Bourgeois gentilhomme
The r letter in French was historically pronounced as a trill, as was the case in Latin and as is still the case in Italian and Spanish. In Northern France, including Paris, the alveolar trill was gradually replaced with the uvular trill during the end of the 18th century. Molière's "Le Bourgeois gentilhomme", published in 1670, has a professor describe the sound of as an alveolar trill (Act II, Scene IV). It has since evolved, in Paris, to a voiced uvular fricative or approximant .