Is database normalization correct?

Question

MySQL

There is such a situation:
Table `artist`. Fields: `arstist_id`, `artist_name`.
The `song` table. Fields: `song_id`, `song_artist`.
It is better to add an artist in the `song_artist` field, and if there are several of them, what should be separated by commas?
Or how, according to the rules of normalization, an intermediate table is needed that links the id of the song and the artist?

Answer 1

1st form - atomicity / done
2nd form - keys / done
3rd form - many-to-many / failed
3rd form
`artist` table. Fields: `arstist_id`, `artist_name`.
The `song` table. Fields: `song_id`, `song_name`.
Table `artist_song`. Fields: `arstist_id`, `song_id`.