[2] Ivana Lang composed orchestral works (concert for piano and orchestra), chamber music, an opera ("The Captain of Kastav", Croatian: Kastavski kapetan) and two ballets, "False Knight" (Lažni vitez) and "Dance of the Ghosts" (Ples sablasti).

Among her famous work was composing music to poems written by Dragutin Domjanić and Antun Gustav Matoš.

In her interesting and very valuable oeuvre (consisting of 110 opus numbers), Ivana Lang paid particular attention to original folk's music idioms, especially from Istria, knowing full well, like all major proponents of this line, that she would be unable to achieve a satisfactory effect with her artistic activity if she was not persistent in promoting and disseminating the art of the people.

Not one of her works inspired by popular strains was a common and conventional folk music picture book, rather a monument to sound in which a creator of so-called serious music, liberally but with great professionalism, making responsible use of the simple ideas of the anonymous originators and first movers from the people, elevated the vernacular sounds to the level of refined art.

Directing all her attention first of all to the sung word, the composer, after that, took to more complex matter, and that was the arrangement of vernacular instrumental dance music.