Question: Between Pelléas et Mélisande and Riders to the Sea, which one has more acts?
Context: Eilene Hannan AM (24 July 194611 July 2014) was an Australian operatic soprano with an international reputation.  She was particularly associated with opera sung in English, although she also sang in other languages.  She was as well known as an actress as she was a singer.  Her repertoire included Mozart's Pamina, Susanna, Cherubino, Dorabella and Zerlina; Mimì in Puccini's "La bohème"; Natasha Rostova in Prokofiev's "War and Peace"; Tatiana in Tchaikovsky's "Eugene Onegin"; Marzelline in Beethoven's "Fidelio"; Mélisande in Debussy's "Pelléas et Mélisande"; Blanche in Poulenc's "Dialogues of the Carmelites"; the title roles in Janáček's "Káťa Kabanová", "Jenůfa" and "The Cunning Little Vixen"; the Marschallin in Richard Strauss's "Der Rosenkavalier"; Princess Eboli in Verdi's "Don Carlos"; Pat Nixon in Adams' "Nixon in China"; Wagner's Sieglinde and Venus; Salome in Massenet's "Hérodiade"; and Monteverdi's Poppea. This is a discography of "Pelléas et Mélisande", an opera by Claude Debussy.  The premiere performance was at the Opéra-Comique in Paris on 30 April 1902.  The list includes all of the studio recordings and also some live performances available on audio CD and DVD. Pelléas et Mélisande ("Pelléas and Mélisande") is an opera in five acts with music by Claude Debussy.  The French libretto was adapted from Maurice Maeterlinck's Symbolist play "Pelléas et Mélisande".  It premiered at the Opéra-Comique in Paris on 30 April 1902 with Jean Périer as Pelléas and Mary Garden as Mélisande in a performance conducted by André Messager, who was instrumental in getting the Opéra-Comique to stage the work.  The only opera Debussy ever completed, it is considered a landmark in 20th-century music. Hector Dufranne (25 October 1870 – 4 May 1951) was a Belgian operatic bass-baritone who enjoyed a long career that took him to opera houses throughout Europe and the United States for more than four decades.  Admired for both his singing and his acting, Dufranne appeared in a large number of world premieres, most notably the role Golaud in the original production of Claude Debussy's "Pelléas et Mélisande" in 1902, which he went on to sing 120 times at that house.  He had an excellent singing technique which maintained the quality of his voice even into the latter part of his career.  His wide vocal range and rich resonant voice enabled him to sing a variety of roles which encompassed French, German, and Italian opera. Pelléas et Mélisande ("Pelléas och Mélisande"), Op.  46, is incidental music by Jean Sibelius for Maurice Maeterlinck's 1892 play "Pelléas and Mélisande".  Sibelius composed in 1905 ten parts, overtures to the five acts and five other movements.  It was first performed at the Swedish Theatre in Helsinki on 17 March 1905 to a translation by Bertel Gripenberg, conducted by the composer). Jean (Alexis) Périer (2 February 1869 – 3 November 1954) was a French operatic baryton-martin and actor.  Although he sang principally within the operetta repertoire, Périer did portray a number of opera roles; mostly within operas by Wolfgang Amadeus Mozart and Giacomo Puccini.  His career was almost entirely centered in Paris and he had a long association with the Opéra-Comique.  He sang in a large number of world premieres, most notably originating the role of Pelléas in Claude Debussy's "Pelléas et Mélisande" in 1902.  In addition to his opera career, Périer appeared in several films between 1900 and 1938. Brett Polegato (born 1968 in Niagara Falls, Ontario, Canada) is an operatic baritone.  In 1999 he made his Lyric Opera of Chicago debut as Peter Niles in Levy's "Mourning Becomes Electra" followed by his La Scala debut in 2000 as Ned Keene in Britten's "Peter Grimes".  He is particularly known for his interpretation of the title role in Debussy's "Pelléas et Mélisande" which he has performed with many companies including the Bavarian State Opera, Opéra National de Paris, Oper Leipzig, and Opéra National du Rhin among others.  Other European appearances include Ubalde in Gluck's "Armide" at Opéra de Nice, the title role in Monteverdi's "Orfeo" at Opéra d'Avignon, and Frère Lèon in Messaien's "Saint François d'Assise" at Opéra National de Paris.  He has sung numerous roles with Flanders Opera, including Guglielmo in Mozart's "Così fan tutte", Albert in Massenet's "Werther", and the Steward in Jonathan Dove's "Flight".  In his native Canada, Polegato has sung Papageno in Mozart's "Die Zauberflöte", Figaro in Rossini's "Il barbiere di Siviglia", and Zurga in Bizet's "Les pêcheurs de perles" with Vancouver Opera.  In the United States, he has sung with New York City Opera, Houston Grand Opera, and Michigan Opera Theatre as well as making many concert appearances and recordings with American orchestras.  He made his Seattle Opera debut in 2005 as Henry Miles in Jake Heggie's "The End of the Affair" and returned to the company in 2007 as Orestes in Gluck's "Iphigenia in Tauris". Riders to the Sea is a short one-act opera by Ralph Vaughan Williams, based on the play of the same name by John Millington Synge.  The composer completed the score in 1927, but it was not premiered until 1 December 1937, at the Royal College of Music, London.  The opera remained largely the province of students and amateurs until it entered the repertoire of Sadler's Wells in 1953. Jeanne Gerville-Réache (26 March 1882 – 5 January 1915) was a French operatic contralto from the Belle Époque.  She possessed a remarkably beautiful voice, an excellent singing technique, and wide vocal range which enabled her to perform several roles traditionally associated with mezzo-sopranos in addition to contralto parts.  Her career began successfully in Europe just before the turn of the twentieth century.  She later came to the North America in 1907 where she worked as an immensely popular singer until her sudden death in 1915.  She is particularly remembered for her portrayal of Dalila in Camille Saint-Saëns' "Samson et Dalila", which she helped establish as an important part of the repertory within the United States.  She also notably portrayed the role of Geneviève in the world premiere of Debussy's "Pelléas et Mélisande" in 1902. The following is a complete list of the orchestral and chamber works of the Finnish composer Jean Sibelius, as well as an incomplete list of works for solo piano, chorus, and voice.  Primarily known for his compositions for orchestra, the core of Sibelius's oeuvre is his set of seven symphonies, the Violin Concerto, and a number of tone poems, in particular "En saga", "Lemminkäinen" (which includes "The Swan of Tuonela"), "Finlandia", "Pohjola's Daughter", "The Oceanides", and "Tapiola".  In addition, works such as the "Karelia Suite", "Valse triste", "Kullervo", "Luonnotar", "Pelléas et Mélisande", "The Tempest", and the String Quartet in D minor, "Voces intimae" have found favor with the public.
Answer: Pelléas et Mélisande