I suspect with AI we always will be in "this story (song, picture) is Ok" and never "is great" category. I recall the member of ABBA was asked whether they ever felt the song would be a hit. She (this was definitely either Agnetha or Anni-Frid) said that never except for "Dancing Queen". So the AI will be able to mimic ABBA-style, but it would struggle to create something like this song.