La serva padrona (The Servant Turned Mistress) is an opera buffa by Giovanni Battista Pergolesi (1710 – 1736) to a libretto by Gennaro Antonio Federico, after the play by Jacopo Angello Nelli.
 The opera is only 45 minutes long and was originally performed as an intermezzo between the acts of a larger serious opera.
 (The same libretto was set by Giovanni Paisiello in 1781.)
Pyotr Ilyich Tchaikovsky's relations with the group of composers known as the Belyayev circle, which lasted from 1887 until Tchaikovsky's death in 1893, influenced all of their music and briefly helped shape the next generation of Russian composers.
 This group was named after timber merchant Mitrofan Belyayev, an amateur musician who became an influential music patron and publisher after he had taken an interest in Alexander Glazunov's work.
 By 1887, Tchaikovsky was firmly established as one of the leading composers in Russia.
 A favorite of Tsar Alexander III, he was widely regarded as a national treasure.
 He was in demand as a guest conductor in Russia and Western Europe, and in 1890 visited the United States in the same capacity.
 By contrast, the fortunes of the nationalistic group of composers known as The Five, which preceded the Belyayev circle, had waned, and the group had long since dispersed; of its members, only Nikolai Rimsky-Korsakov remained fully active as a composer.
 Now a professor of musical composition and orchestration at the Saint Petersburg Conservatory, Rimsky-Korsakov had become a firm believer in the Western-based compositional training that had been once frowned upon by the group.
Nikolai Andreyevich Rimsky-Korsakov (18 March [O.S. 6 March] 1844 21 June [O.S. 8 June] 1908 ) was a Russian composer, and a member of the group of composers known as The Five.
 He was a master of orchestration.
 His best-known orchestral compositions—"Capriccio Espagnol", the "Russian Easter Festival Overture", and the symphonic suite "Scheherazade"—are staples of the classical music repertoire, along with suites and excerpts from some of his 15 operas.
 "Scheherazade" is an example of his frequent use of fairy tale and folk subjects.
Proserpine is a French-language opera by the Italian composer Giovanni Paisiello.
 It takes the form of a "tragédie lyrique" in three acts.
 The libretto, by Nicolas-François Guillard, is a reworking of Philippe Quinault's "Proserpine".
 Paisiello's opera was first performed on 28 March 1803 at the Paris Opéra.
"La partenza" is a 1749 canzonetta by Pietro Metastasio (1698-1782).
 It is among his most famous canzonettas and after being set by the poet himself was set again by many composers including Farinelli, Caffarelli, Giovanni Paisiello, Mozart, Beethoven himself and Beethoven's pupil Archduke Rudolph.
Giovanni Battista Lorenzi (1721–1807) was an Italian librettist.
 He was born and died in (Naples, and was a friend of Giovanni Paisiello, with whom he collaborated on numerous operas.
Nina, o sia La pazza per amore ("Nina, or the Girl Driven Mad by Love") is an opera, described as a "commedia in prosa ed in verso per musica", in two acts by Giovanni Paisiello to an Italian libretto by Giambattista (also "Giovanni Battista") Lorenzi after Giuseppe Carpani's translation of Benoît-Joseph Marsollier's "Nina, ou La folle par amour", set by Nicolas Dalayrac in 1786.
Il re Teodoro in Venezia is a 1784 comic opera by Giovanni Paisiello to a libretto Giovanni Battista Casti.
 Premiered at the Burgtheater Vienna, it was revived for Carnival in Parma in 1788.
Giovanni Paisiello (or Paesiello; 9 May 1740 – 5 June 1816) was an Italian composer of the Classical era.
The Teatro Donizetti is an opera house in Bergamo, Italy.
 Built in the 1780s using a design by architect Giovanni Francesco Lucchini, the theatre was originally referred to as either the Teatro Nuovo or Teatro di Fiera.
 The first opera to be mounted at the theatre, Giuseppe Sarti's "Medonte, re di Epiro", was in 1784 while the opera house was still under construction.
 The official opening of the house, under the name the Teatro Riccardi, did not occur until 24 August 1791 with a production of Pietro Metastasio's "Didone abbandonata" set to music by multiple composers, including Ferdinando Bertoni, Giacomo Rampini, Johann Gottlieb Naumann, Giuseppe Gazzaniga, and Giovanni Paisiello.

Question: Are Nikolai Rimsky-Korsakov and Giovanni Paisiello both composers?
Answer: yes