I have looked at examples from their YouTube channels and their twitter accounts and Facebook.
For Justin Bieber, he has his new album out and is trying to get people to buy his songs. On his Facebook he has the album covers, so that the fans can easily find the songs. And on his Twitter he has a link to his song 'Cold Water' which is available to the fans. On both all his social medias, he has a photo of himself in black and white which is on the front on his album cover as well.
Skrillex's brand is simple and uses a jagged type of font with black and red colours to signify his type of music. On his Instagram he has a link to his YouTube Channel and his SnapChat name so that his fans can follow him and what he is doing. Skrillex also has a picture of himself on his social medias, one where he is with other people and the other of him alone in black and white.
Diplo is a DJ, his YouTube Channel has the picture for the song 'Cold Water' and has the name of the people involved including himself. His profile picture is of him but in colour and very bright lighting.
For Calvin Harris, there is a photo of himself in a bright light and his banner has an advertisement for his new song which he is saying is available to the public.
For the Chainsmokers, they have a very bright colourful photo of them and they also are advertising their new track.
Avicii's social media branding is quite plain and not an example I would use as it doesn't stand out to an audience enough, his use of grey colouring is slightly dim.