select music_name from
(
# 查询关注者喜欢的歌曲id(过滤1用户喜欢的歌曲id)    
select l1.music_id flove_id
from
(
#查询1用户的关注者id
select follower_id 
from follow 
where user_id=1
) t
left join music_likes l1
on follower_id=l1.user_id

# 过滤1用户喜欢的歌曲id
where l1.music_id not in
(select music_id
from music_likes
where user_id=1
)) t1

left join music m
on m.id=t1.flove_id

group by m.id
order by m.id
;

做一步就要执行一步确保正确