These 4 Préludes for flute (treble [alto] recorder or txistu in f) and piano are originally written for txistu and follow the ambitus of the Basque instrument. The initial Prélude, Allegro, is marked by its joyous character, its aksak rhythm (3+3+2), its generous modulations and its uninterrupted flow in the spirit of the Humoresque. The second Prélude, Moderato, is distinguished by a softer expression, a principle of ornamental variation, combined with a search for tonal diversity. The third Prélude, also Moderato, is in ternary rhythm with long expressive melodic lines accompanied by chords in amphibraque rhythm. The conclusive Presto is a saltarello developed in a game of tight modulations