There are completely fake bands, who are 'on tour', 'giving interviews', cranking out albums. Like "Shunned at a Funeral" [0] for instance, an AI Christian rock band. Mentioning nowhere that it is all fake.
Here is a band member of the real band "Wings of Pegasus" who takes a closer look at these shenanigans in "Are you sure your favourite band is real?" [1]
You could say almost the same about Gorillaz except for the AI part.