Pierre-Alain Four is an author and stage director: he designs musical performances, drawing his inspiration mainly from the Baroque repertoire and classical music.

With the Ensemble Boréades, of which he is the founder, Pierre-Alain Four has written and directed over twenty productions, including the Castrats / Divas / Rockers trilogy and Renaissance à la Carte (for four a cappella singers). Other notable works include 2000 fois Butterfly (about the life of a Japanese singer) and Les Bijoux, la Maîtresse et François 1er, two short works that combine music, storytelling and video.

Pierre-Alain Four also works regularly with other companies and ensembles, including the Brins de Voix ensemble (directed by Fanny Mouren and Caroline Adoumbou), for whom he has directed Cosi fan Tutte and Don Giovanni and is preparing Les Noces de Figaro, and the Epsilon ensemble (directed by Maud Hamon). He is currently working on a show with the ensemble Artifices (conducted by Alice Julien-Laferrière).

L'affaire Bach is his third collaboration with Le Concert de l'Hostel Dieu, following Shakespeare (still) in love and Apollon & Hyacinthe.