This is the 310th most frequent Bulgarian word.
българския
"Българския" means "the Bulgarian" in English, referring to the language or something related to Bulgaria.
In this sentence, "българския" describes "фолклор" (folklore), emphasizing the specific cultural aspect of Bulgaria.
Обичам българския фолклор.
I love Bulgarian folklore.
The word "българския" acts as an adjective defining the noun "стил" (style), contextualizing the type as related to Bulgaria.
Тази песен е в българския стил.
This song is in the Bulgarian style.
Here, "българския" is used as an adjective modifying the noun "език" (language) to specify that it refers to the Bulgarian language.