Here's a name for you:
Butch Walker
I saw him live in 2003 and have been a fan ever since. He's managed to make some money in the meantime but he's by no means a big mainstream star even though he has 100X the talent of a Bieber.
In the same vein, does it bother anyone else how Disney makes almost every single indentured servant, er, kid actor into a pop singer these days? Half their shows are about kid performers for crying out loud. As if kids everywhere have performing artist jobs as singers or dancers. Seriously, I think Disney is run by Satan.