Question: What occupation did George Gershwin and Jacques Offenbach share?

Context articles: List of compositions by Jacques Offenbach
George Gershwin
Oscar Peterson Plays George Gershwin
Le château à Toto
Oscar Peterson Plays the George Gershwin Songbook
Jacques Offenbach
Mesdames de la Halle
Fantasio (Offenbach)
Le financier et le savetier
La Périchole

This is a list of musical compositions by Jacques Offenbach (1819–1880).
 Offenbach is principally known for his operettas, of which he composed 98 between 1847 and 1880.
 He also wrote two opéras, "Die Rheinnixen" and his unfinished masterpiece "Les contes d'Hoffmann".
George Jacob Gershwin ( ; September 26, 1898 July 11, 1937) was an American composer and pianist.
 Gershwin's compositions spanned both popular and classical genres, and his most popular melodies are widely known.
 Among his best-known works are the orchestral compositions "Rhapsody in Blue" (1924) and "An American in Paris" (1928) as well as the opera "Porgy and Bess" (1935).
Oscar Peterson Plays George Gershwin is a 1952 album by pianist Oscar Peterson of popular songs written by George Gershwin and Ira Gershwin.
 Several tracks were included on the 1959 album "Oscar Peterson Plays the George Gershwin Songbook".
Le château à Toto ("Toto’s castle") is an opéra bouffe in three acts of 1868 with music by Jacques Offenbach.
 The French libretto was by Henri Meilhac and Ludovic Halévy.
 It is situated in an important sequence of fifteen opera works and revivals by Offenbach between 1867 and 1869.
Oscar Peterson Plays the George Gershwin Songbook is a 1959 album by pianist Oscar Peterson of compositions written by George Gershwin.
 Peterson had recorded many of the pieces for his 1952 album "Oscar Peterson Plays George Gershwin".
Jacques Offenbach (] ; ] ; 20 June 1819 – 5 October 1880) was a German-born French composer, cellist and impresario of the romantic period.
 He is remembered for his nearly 100 operettas of the 1850s–1870s and his uncompleted opera "The Tales of Hoffmann".
 He was a powerful influence on later composers of the operetta genre, particularly Johann Strauss, Jr. and Arthur Sullivan.
 His best-known works were continually revived during the 20th century, and many of his operettas continue to be staged in the 21st.
 "The Tales of Hoffman" remains part of the standard opera repertory.
Mesdames de la Halle is an opérette bouffe in one act by Jacques Offenbach, with a libretto by Armand Lapointe.
 It was first performed at the Théâtre des Bouffes Parisiens, Paris on 3 March 1858.
 and was the first work of Offenbach's at the Bouffes with a chorus and a large cast.
 Gänzl describes the piece as “a delicious piece of Parisian bouffonerie”
Fantasio is an 1872 opéra comique in 3 acts, 4 tableaux with music by Jacques Offenbach.
 The French libretto by Paul de Musset was closely based on the 1834 play of the same name by his brother Alfred de Musset.
 The opera found little success in Offenbach's lifetime, was revived in the 1930s and performed in a critical edition in the 2000s.
Le financier et le savetier (The financier and the cobbler) is a one-act opérette bouffe of 1856 with words by Hector Crémieux and Edmond About, and music by Jacques Offenbach, based on the poem by La Fontaine.
 In 1842 Offenbach had set "The Cobbler and the Financier" ("Le Savetier et le Financier") among a set of six fables of La Fontaine.
La Périchole (] ) is an opéra bouffe in three acts by Jacques Offenbach.
 Henri Meilhac and Ludovic Halévy wrote the French-language libretto based on the 1829 one act play "Le carrosse du Saint-Sacrement" by Prosper Mérimée, which was revived on 13 March 1850 at the Théâtre-Français.
 Offenbach was probably aware of this production, as he conducted the orchestra of the Comédie-Française from around this time.
 Another theatrical creation that pre-dates Offenbach's opéra bouffe and may have influenced the piece is a farce by Desforges and Théaulon given on 21 October 1835 at the Théâtre du Palais-Royal.