Is it ever okay for an artist to use the creations (music, dance, fashion, etc.) of artists from a different racial/ethnic group? Does it matter which races are involved? What if credit is given to the creators?

It is not okay. Unless the artist learned about the culture but if they don’t they are doing cultural appropriation. It definitely matters what race is involved a white artist can’t do a Chicana (Mexican culture) music. Even if credit is given they should respect the culture