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 not to be preceded by H and is indicated by a comma above the vowel. In the Greek for sixtieth year (transliterated as hexèkoston etos) the initial epsilon of the first word hasa rough breathing sign while the epsilon of the second has a smooth one.
| Instrument (fx guitar, sang m.m.) | Flųjte, Klarinet |
| Sideantal | 12 |
| Media (fx Bog, CD, DVD m.m.) | Bog(softcover, hęftet) |
| Publisher/Producent | Boosey and Hawkes |
| Bidragydere | Carter, Elliott(Composer) |
| ISMN | 9790051102518 |