Esprit Rude/Esprit Doux for flute and clarinet was composed for the celebration of Pierre Boulez's 60th birthday on March 31, 1985 in Baden-Baden. The title, translated as rough breathing/smooth breathing, refers to the pronunciation of classical Greek words beginning with a vowel or an “R”. With “Esprit Rude” (rough breathing) the initial vowel (or R) is to be preceded by a sounded H, and is indicated by a reversed comma above the letter. With Esprit Doux (smooth breathing) the initial vowel is...