Could you list the names of all artists that prefer the genre folk and speak the language Bangla?
SELECT T1.artist_name FROM artist AS T1 JOIN song AS T2 ON T1.artist_name  =  T2.artist_name WHERE T2.languages  =  "bangla" AND T1.preferred_genre  =  "folk"
artists that prefer the genre folk refers to preferred_genre = 'folk'; speak the language Bangla refers to languages = 'bangla'; listing names of all artists refers to SELECT artist_name;