Ideologically grounded aesthetic worldviews never inhibited Papandopulo in his choice of non-musical subjects for his own works; he always found, in each one of them, universal ideas, profound human values. At the beginning of this work he found non-musical stimuli in topics related to the older strata of the folk tradition – in “legends, rites and myths” ("Svatovske / Bridal, Dodolice", a Folk Ritual for the Solo Soprano, Piano and Girl's Choir Op 2, "Zlato / Gold, Utva zlatokrila / Ruddy Shellduck"). Later, after 1950, very curiously, he drew his inspiration from apparently diametrically opposed worldviews. At the same time he would write compositions of religious topics – from the Croatian Catholic mass with traces and elements of Glagolitic chant ("Osorski rekvijem / Osor Requiem, Pučka poljička misa / Folk Mass from Poljica", the cantata "Jubilate" and a number of smaller religious works) and also monumental works of socialist realism (inspired by the ideology and poetics of the post-war socialist revolution and the People's Liberation War, such as the musical-poetical work "Pasija po srcu / Passion After the Heart", the poetic-musical vision "Credo", 1943 – cycle of songs to words by Ivan Goran Kovačić) as well as those inspired by Croatian history (the cantatas "Libertas, Pohvala Dubrovniku" / "In Praise of Dubrovnik, Non bene pro toto libertas venditur auro", "Mile Gojslavica" and the triptych for mixed voice choir and large symphony orchestra "Istarske freske / Istrian Frescos" and so on).