Давно хотел спросить у знатоков
Ну и чем, на обывательский слух, пресловутый гимн "Гей, славяне" отличается от "Еще Польска не згинела"?

Впрочем, вот интересное объяснение с "Википедии":

Mazurek Dabrowskiego
Mazurek Dąbrowskiego (Dąbrowski's Mazurka) is the Polish national anthem written by Józef Wybicki in 1797.
At first called the 'Song of the Polish Legions in Italy' (Pieśń Legionów Polskich we Włoszech), it also has the informal name Jeszcze Polska nie zginęła, from its first line, which is sometimes erroneously taken to be the Polish state motto.
The song gained much popularity in Poland and became one of the most popular hymns during the November Uprising of 1830 and January Uprising of 1863. During the Revolutions of 1848 it became popular throughout Europe as one of the revolutionary anthems in Berlin, Vienna, Prague and Paris. This led Slovak poet Samuel Tomašik to write the anthem, Hey, Slavs, based on the melody of Mazurek Dąbrowskiego, later accepted by the First Congress of the Pan-Slavic Movement in Prague as the Pan-Slavic Anthem. During the Second World War the translation of this anthem became the national anthem of Yugoslavia. Other famous versions of the anthem include Shumi Maritsa, the national anthem of Bulgaria between 1886 and 1944.

То есть гимн Польши и гимн Югославии отличались только текстом. Что характерно.