As for Italian works, I've been singing for six years, and I haven't seen any of them … I can't help you … but I'd like to introduce you to some foreign classic works.
Austria: Polka, Emperor Waltz, Spring Waltz and Blue Danube are all accompanied by steel.
Hungary: "On the Peak" and "Song of the Evening" are all unaccompanied.
English: This is the May Festival without accompaniment.
Fred: Ode to the Virgin has a steel companion.
Gypsy: "Happy Gypsy" (also called "Sucking Slag") is difficult without company.
Russia: "Spring Tide" is accompanied by steel [difficult]
Don't think it's easy to have an accompaniment. All the above are world famous songs, which are suitable for college students to sing and reflect their level. I hope they can help you.