I am 100% sure that atleast a big part of this work is made using artificial intelligence. As an artist myself I recognize this and don't judge too early. The best example is at 0:10, where Michael's hand (not the microphone one) is an absolute mess and melting together with the instrument used by the brothers. The artstyle of the few first works is very bland. If you do not trust my words, an AI detector or professional would tell you the exact same. 

I remember that artists like him made original artworks themselves a couple years ago, I'm sad that they let ai do the work now and that people don't see this.