De profundis, composed in 1834 but left unfinished, is a watershed in Liszt's development as a composer. This 'instrumental psalm' for piano and orchestra, lasting over 30 minutes, was inspired by Liszt's relationship with the Abbé Félicité de Lamennais. Lamennais' person and his book Paroles d'un croyant made such an impression on the 23-year-old musician that he dedicated De profundis to him. The only surviving source for the work is Liszt's working score. Although the music is not fully e...