During the next two hundred years, zarzuela, as these mixed entertainments swiftly became known, became the native-language alternative to the Italian operatic form nurtured by successive monarchs.
Isabella II fell from power during the liberal revolution of 1868, and the country found itself submerged in a crisis at all levels: economic, political, and ideological (with various strands of socialism coming to prominence).
Such high prices, plus the national uncertainty, brought most Madrid theatres into crisis, and many - including the Teatro de la Zarzuela itself - came close to ruin.
The comedic model for these featured zany, unpredictable plots based on myths, tending towards caricature and mockery of various topics such as royalty, the Army, and politics.
Because of the need for short operetta-like works that could fit into one hour, the first performances were of old plays that were already popular, such as El Maestro de baile ("The Dancing Master", by Luis Misón, and predating the género chico by many years), or plays like Una vieja ("An Old Woman", Joaquín Gaztambide) and El grumete ("The Cabin Boy", Emilio Arrieta).
Unlike the serious, dramatic themes and complicated plots in zarzuela mayor, this genre presented simplified farces about everyday topics such as daily life in Madrid.
The decade of the 1870s saw the genre consolidate itself, with numerous authors publishing, for example Miguel Nieto and his El Gorro Frigio ("The Phrygian Cap"), and Fernández Caballero's Château Margaux.
His work includes El año pasado por agua ("Last Year Under Water"), Agua, azucarillos y aguardiente ("Water, Sweets, and Spirits"), perhaps the most popular nowadays, La alegría de la huerta ("The happiness of the orchard"), El arca de Noé ("Noah's Ark"), Los descamisados ("The Shirtless Ones") and more.
Other important playwrights were Giménez, Joaquín "Quinito" Valverde Sanjuán (Joaquín Valverde Durán's son), Tomás Lopez Torregrosa (San Antón and El santo de la Isidra ["Isidra's Saint", Isidra being one of the characters]) Fernández Caballero (El dúo de la africana [The Duet from L'Africaine, a reference to the opera by Meyerbeer], El cabo primero ["The Headman", that is, the person in command], La viejecita ["The Little Old Lady"], and Gigantes y cabezudos ["Giants and cabezudos"]; named after popular Spanish parade disguises), Jerónimo Jiménez (El baile de Luis Alonso ["The Dance of Luis Alonso"] and its sequel La boda de Luis Alonso ["The Marriage of Luis Alonso"]).
One very important auteur was Ruperto Chapí, who spent his life oscillating between attempts to create a proper Spanish opera, and his modest género chico plays, which included Música Clásica ("Classical Music"), La revoltosa ("The Rebel Girl"), ¡Las doce y media y sereno!
Whilst the critics were harsh with the genre, it was a great success with the public and was adopted by a few more theatres, to the point where it took over the Variedades theater, which the decline of comic opera had left free, and which was already a venue of some note.
The sainete, established in its definitive form by Ramón de la Cruz, is the direct heir of the comic interludes or brief farces that were previously so popular.
Moreover, as a unique characteristic of the genre, the constant presence of open-air parties, often at night, which appear at the beginning of the plays in order to situate them and at the end as dénouement.
The género chico was always fiercely current: the actors make references (often in the songs, into which extra verses are added) to the outside world, with this "news" aspect of the play being even more important than the actual plot.
Furthermore, pronounced, popular rhythms are sought in the dance halls, generally imported but "nationalised", such as the chotis (from the German Schottisch, its ultimate origin being in Scotland), and many others, such as boleros, fandangos, or habaneras from Latin America, jotas, seguidillas, soleás, pasacalles, and waltzes, polkas, or mazurcas from Poland.