Question: What type of classical music are Claudio Monteverdi and Giacomo Meyerbeer best know for composing?
Context: Giovanni Valentini (ca. 1582 – 29/30 April 1649) was an Italian Baroque composer, poet and keyboard virtuoso.  Overshadowed by his contemporaries, Claudio Monteverdi and Heinrich Schütz, Valentini is practically forgotten today, although he occupied one of the most prestigious musical posts of his time.  He is best remembered for his innovative usage of asymmetric meters and the fact that he was Johann Kaspar Kerll's first teacher.  The family name comes from deep roots in the native country of Greece.  Well known for their classical music but also known for the family that branched off to the neighbouring country of Italy. Baroque music ( or ) is a style of Western art music composed from approximately 1600 to 1750.  This era followed the Renaissance music era, and was followed in turn by the Classical era.  Baroque music forms a major portion of the "classical music" canon, being nowadays widely studied, performed, and listened to.  Key composers of the Baroque era include Johann Sebastian Bach, Antonio Vivaldi, George Frideric Handel, Claudio Monteverdi, Domenico Scarlatti, Alessandro Scarlatti, Henry Purcell, Georg Philipp Telemann, Jean-Baptiste Lully, Jean-Philippe Rameau, Marc-Antoine Charpentier, Arcangelo Corelli, Tomaso Albinoni, François Couperin, Giuseppe Tartini, Heinrich Schütz, Giovanni Battista Pergolesi, Dieterich Buxtehude, and Johann Pachelbel. Claudio Giovanni Antonio Monteverdi (] ; 15 May 1567 (baptized) – 29 November 1643) was an Italian composer, string player and choirmaster.  A composer of both secular and sacred music, and a pioneer in the development of opera, he is considered a crucial transitional figure between the Renaissance and the Baroque periods of music history. Aaron Halle-Wolfssohn (1754 or 1756, in probably Halle – 20 March 1835, in Fürth) was a German Jew, a translator and commentator of the "Tanakh" and a leading writer of the "Haskalah" (the Jewish Enlightenment).  He was born in Halle and died in Fürth.  He was professor at the Königliche Wilhelmsschule at Breslau from 1792 to 1807.  After 1807, private professor in Berlin of the Meyerbeer brothers, and Giacomo Meyerbeer in particular.  Some letters between Giacomo Meyerbeer and Aron Wolfssohn were published among the Meyerbeer correspondence. Giacomo Meyerbeer (born Jacob Liebmann Beer; 5 September 1791 – 2 May 1864) was a German opera composer of Jewish birth who has been described as perhaps the most successful stage composer of the nineteenth century.  With his 1831 opera "Robert le diable" and its successors, he gave the genre of grand opera 'decisive character'.  Meyerbeer's grand opera style was achieved by his merging of German orchestra style with Italian vocal tradition.  These were employed in the context of sensational and melodramatic libretti created by Eugène Scribe and were enhanced by the up-to-date theatre technology of the Paris Opéra.  They set a standard which helped to maintain Paris as the opera capital of the nineteenth century. Joan Catoni Conlon is Professor and Director of Graduate Choral Research Emerita for the University of Colorado at Boulder, where she conducted the University Singers.  She received her BA, MA and DMA degrees from the University of Washington where she was Professor of Choral Music and Conducting (1972–95).  From 1971 to 1995 she was the conductor of the Northwest Chamber Chorus in Seattle, Washington, and was the chair of the Research and Publications Committee of the American Choral Directors Association.  Her scholarship specializes in the choral music of Georg Philipp Telemann and Claudio Monteverdi.  She published "Performing Monteverdi: A Conductor’s Guide" (ISBN  ).  She has also studied the Hindustani classical vocal music of India.  In 2009 she edited and contributed to 'Wisdom, Wit and Will: Women Choral Conductors On their Art' ISBN  .]  -- a collection of essays relating to conducting choral literature and professional development. John Whenham is an English musicologist and academic who specializes in early Italian baroque music.  He earned both a Bachelor of Music and a Master of Music from the University of Nottingham, and a Doctor of Philosophy from the University of Oxford.  He is a leading expert on the life and works of Claudio Monteverdi, and is the author of the books "Duet and Dialogue in the Age of Monteverdi" (Ann Arbor, Michigan: University Microfilms International, 1982) "Monteverdi, 'Orfeo' " (London: Cambridge University Press, 1986), "Monteverdi, Vespers (1610)" (Cambridge University Press, 1997), and "The Cambridge Companion to Monteverdi" (with Richard Wistreich, Cambridge University Press, 2007).  For five years he was co-editor of the journal "Music & Letters".  He currently serves on the board of the Birmingham Early Music Festival and is head of the music history department at the University of Birmingham. Nigel David Rogers (born 21 March 1935) is an English multilingual tenor, music conductor, singing teacher and vocal coach, who has sung in over seventy classical music album recordings in German, French, Italian, Latin and English, mostly of early music, baroque and sacred music, including works by Claudio Monteverdi, Handel, Purcell, and Bach.  Singing critics like Melanie Eskenazi describe him as a vocal virtuoso of the local phrasing and decoration (ornamenti) of those particular musical periods exactly as they were practised back then.  He is considered a world authority in the field of European early music, the scores of which he helped promote and rescue as a music genre, since the outset of his early career. These lists show the audio and visual recordings of the opera "L'Orfeo" by Claudio Monteverdi.  The opera was first performed in Mantua in 1607, at the court of Duke Vincenzo Gonzaga, and is one of the earliest of all operas.  The first recording of "L'Orfeo" was issued in 1939, a freely adapted version of Monteverdi's music edited by Giacomo Benvenuti, given by the orchestra of La Scala Milan conducted by Ferrucio Calusio.  In 1949 the Berlin Radio Orchestra under Helmut Koch recorded the complete opera, on long-playing records (LPs).  The advent of LP recordings was, as Harold Schonberg later wrote, an important factor in the postwar revival of interest in Renaissance and Baroque music, and from the mid-1950s recordings of "L'Orfeo" have been issued on many labels.  Koch's landmark version was reissued in 1962, when it was compared unfavourably with others that had by then been issued.  The 1969 recording by Nicholas Harnoncourt and the Vienna Concentus Musicus, using Harnoncourt's edition based on period instruments, was praised for "making Monteverdi's music sound something like the way he imagined".  In 1981 Siegfried Heinrich, with the Early Music Studio of the Hesse Chamber Orchestra, recorded a version which re-created the original Striggio libretto ending, adding music from Monteverdi's 1616 ballet "Tirsi e Clori" for the Bacchante scenes.  Among more recent recordings, that of Emmanuelle Haïm has been praised for its dramatic effect.  The 21st century has seen the issue of an increasing number of recordings on DVD. The Stattkus-Verzeichnis (SV) is a catalogue of the musical compositions of the Italian composer Claudio Monteverdi.  The catalogue was published in 1985 by Manfred H. Stattkus ("Claudio Monteverdi: Verzeichnis der erhaltenen Werke").  A free, basic second edition of the catalogue is available online.
Answer: opera