During the 1835-48 heyday of the Illyrian Movement, patriotic songs became popular among the Croatian urban middle classes; they were known (also in the Serbian lands) as davorije (later rebranded budnice). They were short, one-voice choruses, usually in a march rhythm with a simple melody. Their lyrics celebrated the Croatian past, culture, and countryside, and proclaimed the struggle for national emancipation and Slavic unity, sometimes overtly (Oj, Ilirijo, oj, veselo nam stoj, “Oy, Iliria, oy, be joyful”; Uviek složno treba poći, “Always going in harmony”), sometimes metaphorically coded (Prosto zrakom ptica leti, “The bird flies free in the air”).

The prototype was created in 1833 by the two leaders of the national movement: Ljudevit Gaj wrote the verse Horvatov sloga i zjedinjenje (“Croats’ harmony and unity”; better known by its first line, Još Hrvatska ni propala, “Croatia hasn’t fallen yet”); it was set to music by Ferdo Wiesner Livadić. The song spread throughout Croatia at a rapid speed and became a rallying song for the supporters of the Illyrian movement. The text echoed the Polish patriotic anthem Joszcze Polska nie zginęła kiedy my żyjemy (“Poland hasn’t died yet, because we live”).

Davorije not only became popular as mass-participation performances during public events, they also entered concert life; foreign musicians appearing in Croatia found themselves compelled to include them in their concert programmes. The Hungarian composer Anton Ebenhöch, who played in Zagreb in 1836, performed variations of the song Nek se hrusti šaka mala (in its original version containing the anti-Hungarian text). The same song appeared in the concert of the Bratislava Musikverein in 1839; the performance, starring Dragutin Klobučarić (1794–1886), elected representative of the city of Karlovac at the 1839 Parliament Assembly in Bratislava, was enthusiastically received by the audience, including the Hungarian delegation at the Assembly, which failed to get its anti-Hungarian drift. The same theme was again used for sets of variations by other composers as well. The flautist Franjo Ksaver Čačkovic-Vrhovinski (1789–1865) composed Uvod i promene sjajne za flautu sverhu uzljubljenog ilirzkog napeva “Iz Zagorja od prastara” (“Introduction and brilliant variations for flute on the appreciated Illyrian song Iz Zagorja od prastara”) for orchestra, dedicated to Ljudevit Gaj.

Such compositions used the style and mannerisms which at the time were understood in northern Croatia as folk music. That style came out of the musical expression of the middle class and the lower nobility, which carried out the ideas of the movement, rather than that of the rural population. Several times over the century, when anti-national repressive governments were in power (1867-73, 1883-1903), musical life became spontaneously politicized and the Illyrian-period budnice enjoyed new popularity.

Concert music in 19th-century Croatia was dominated, alongside Livadić, by the composers/conductors Vatroslav Lisinski and Ivan Zajc.

Lisinski was born in 1819 in Zagreb to a Slovenian father and a Croatian mother. Having received a private musical education, he was invited in 1840-41 to become the conductor of the first Illyrian choral society, run by Alberto Štriga (1821–1897). His song Prosto zrakom ptica leti to words by Dimitrija Demeter (1841) is still popular today, but his best-known composition from these years is the opera Ljubav i zloba (“Love and rancour”, 1846). The “national” character of the opera is proclaimed not only in its Croat-language libretto (on a plotline by Štriga, and with improvements by Demeter), but also in its occasional use of themes from Slovene and Croat folk music. With Štriga and Ferdo Livadić, Lisinski toured Serbia in 1847 (Belgrade, Pančevo, Novi Sad, Mitrovica) with a small troupe of singers performing Croatian and Serbian songs. In 1847 he moved to Prague, where he took private music lessons, being too old to enrol in the conservatorium. In 1850 he returned to Zagreb, where his lack of a formal diploma – as well as post-1848 political suspicion of his Illyrian patriotism – prevented a full-time professional career in music. His second opera, Porin (libretto by Demeter), begun in Prague, was finished in 1851 but only performed posthumously, in 1897. Lisinski died in 1854 at the age of 34 years. His death left a void which was only filled in the 1860s by Ivan Zajc.

Ivan Dragutin Stjepan Zajc (the family name was originally spelled Zajitz or Zaytz) was born in Rijeka in 1832 to a Bohemian father who was music master of an army regiment. From 1850 to 1855 Zajc studied music at the conservatorium of Milan; in 1855 he took over his father’s regimental post, and became the conductor of Rijeka’s orchestra and a teacher at the city’s philharmonic institute. In 1862 he moved to Vienna, where he taught at the Polyhymnia choral and operatic society and obtained success with his operetta Mannschaft an Bord (1863). In the course of the 1860s he was encouraged to move to Zagreb by  Strossmayer and Preradović, where – following a fallow period of repressive absolutism – an opera house was established; Zajc became its first director in 1870, and continued in that function until 1889. His most famous opera was the national-historical Nikola Šubić Zrinjski (1876), on the 16th-century national hero.