omitted the Dies irae, though reference to the day of judgment appears in the Libera me, which, like Verdi, he added to the normal liturgical text. Fauré revised the Requiem over the years, and a number of different performing versions are now in use, from the earliest, for small forces, to the final revision with full orchestra. Fauré's operas have not found a place in the regular repertoire. Prométhée is the more neglected of the two, with only a handful of performances in more than a century. Copland considered Pénélope (1913) a fascinating work, and one of the best operas written since Wagner; he noted, however, that the music is, as a whole, "distinctly non-theatrical." The work uses leitmotifs, and the two main roles call for voices of heroic quality, but these are the only ways in which the work is Wagnerian. In Fauré's late style, "tonality is stretched hard, without breaking." On the rare occasions when the piece has been staged, critical opinion has generally praised the musical quality of the score, but has varied as to the dramatic effectiveness of the work. When the opera was first presented in London in 1970, in a student production by the Royal Academy of Music, Peter Heyworth wrote, "A score that offers rich rewards to an attentive ear can none the less fail to cut much ice in the theatre. ... Most of the music is too recessive to be theatrically effective." However, after a 2006 production at the Wexford Festival, Ian Fox wrote, "Fauré's Pénélope is a true rarity, and, although some lovely music was anticipated, it was a surprise how sure the composer's theatrical touch was." Piano works Fauré's major sets of piano works are thirteen nocturnes, thirteen barcarolles, six impromptus, and four valses-caprices. These sets were composed across the decades of his career, and display the change in his style from uncomplicated youthful charm to a final enigmatic, but sometimes fiery introspection, by way of a turbulent period in his middle years. His other notable piano pieces, including shorter works, or collections composed or published as a set, are Romances sans paroles, Ballade in F major, Mazurka in B major, Thème et variations in C minor, and Huit pièces brèves. For piano duet, Fauré composed the Dolly Suite and, together with his friend and former pupil André Messager, an exuberant parody of Wagner in the short suite Souvenirs