Complex sentence: The libretto was written by Béla Balázs, a poet and friend of the composer, and is written in Hungarian, based on the French literary tale "La Barbe bleue" by Charles Perrault.
Split into simpler sentences: The libretto was written by Béla Balázs, a poet and friend of the composer. It is in Hungarian, based on the French literary tale "La Barbe bleue" by Charles Perrault.