This is the 7691st most frequent Polish word.
ludowego
"Of the people" or "folk."
In this case, 'ludowego' is used to qualify 'Poland's dances', associating them with folk culture or traditions.
Czytałem książkę na temat tańców ludowego Polski.
I read a book about Poland's folk dances.
In this sentence, 'ludowego' is used to describe 'art', specifying it as belonging to the folk or traditional genre.
Chodziłem dziś do muzeum sztuki ludowego.
Today, I went to the museum of folk art.
Here, 'ludowego' modifies 'music', characterizing it as folk or traditional in nature.