select music_name
from music_likes ml join music m on ml.music_id = m.id
where user_id in (select follower_id from follow where user_id = 1)
and music_id not in (select music_id from music_likes where user_id =1)
group by music_id 
order by m.id

先找到user_id 1关注的id，然后排除掉user_id 1喜欢的歌曲id 就OK了